Biomedical subjects

S W Weiss

Publications and source records attributed to S W Weiss.

At least 37 records · Page 2Linked to original sources

PubMed2000

Cutaneous angiosarcoma arising in a gouty tophus: report of a unique case and a review of foreign material-associated angiosarcomas.

Rare cases of angiosarcoma have been reported to arise in the setting of retained foreign material or in association with arteriovenous fistulae. No previous case of angiosarcoma, or any other malignancy, has been reported to arise with a gouty tophus. We present a case of an 86-year-old man with a high-grade angiosarcoma that arose within a long-standing tophus.

Aged↗

PubMed2000

Sarcomas arising in dermatofibrosarcoma protuberans: a reappraisal of biologic behavior in eighteen cases treated by wide local excision with extended clinical follow up.

There is a prevailing view that sarcomas arising in dermatofibrosarcoma protuberans (DFSP) have a higher risk of metastasis than ordinary DFSP, but these data are based on cases with variable and often suboptimal treatment. There has not been a large study of sarcomas arising in DFSP in which all cases were treated by wide local excision, thereby arguably altering outcome. Clinicopathologic features of 18 cases of sarcomas arising in DFSP treated by wide local excision and having follow up of at least 5 years were analyzed. An estimate of the proportion of sarcoma and DFSP was made. The number of mitotic figures and degree of CD34 immunoreactivity were assessed in each case. The cohort included 13 females and 5 males (age, 23-87 yrs; median, 47 yrs). The tumors involved the trunk (7), scalp (4), extremities (4), and inguinal region (3), and ranged from 1.5 to 7 cm (median, 4 cm). Sarcoma occurred de novo in 15 cases and in a recurrence in three. Sarcomas resembled fibrosarcoma (17) or malignant fibrous histiocytoma (1) and occupied between 20% and 80% of the tumor (median, 60%). Mitotic activity ranged from 2 to 16 per 10 high-power field (HPF; median 7 per 10 HPF) in the sarcomatous component and 0 to 3 per 10 HPF (median, 1 per 10 HPF) in the DFSP component. All tumors expressed CD34 in the DFSP component but only nine (50%) in the sarcomatous component. All patients were treated by wide local excision with negative margins; three additionally received radiation. Four patients (22%) developed recurrences, but none developed metastasis during the follow-up period of 62 months to 17 years (median, 81.5 mos). In contrast to earlier studies, we demonstrate that patients with sarcomas arising in DFSP do not have an increased risk of distant metastasis within a 5-year follow-up period, provided they are treated by wide local excision with negative margins. This probably reflects the fact that wide local excision results in eradication of local tumor, thereby eliminating the source for subsequent dissemination. However, we cannot completely exclude the possibility that tumors in which clear margins are achieved represent a less aggressive subset, as has been suggested for high-grade extremity sarcomas. Previous studies showing increased metastasis for sarcomas arising in DFSP should be re-evaluated to determine if, with treatment stratification, metastatic rate varies.

Adult↗

PubMed2000

Clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres: a novel member of the perivascular epithelioid clear cell family of tumors with a predilection for children and young adults.

The perivascular epithelioid cell family of tumors (PEComas), defined by their co-expression of melanocytic and muscle markers, includes angiomyolipoma, lymphangioleiomyoma, and clear cell "sugar" tumors of the lung, pancreas, and uterus. We present seven cases of a unique and previously unrecognized tumor of children and young adults, which represents a new addition to the PEComa group of tumors. Culled from three institutions over a 50-year period, all cases occurred in or immediately adjacent to the ligamentum teres and falciform ligament. Six patients were female and one male; their ages ranged from 3 to 21 years (median, 11 yrs). Tumor sizes ranged from 5 to 20 cm (median, 8 cm). All cases consisted of clear to faintly eosinophilic spindled cells arranged in fascicular and nested patterns. The cells had small but distinct nucleoli and low mitotic activity. Immunohistochemically, all cases were positive with antibodies to gp100 protein (HMB-45) and negative for S-100 protein. In three of the seven cases studied immunohistochemically, the tumors expressed smooth muscle actin, melan-A, microphthalmia transcription factor (MiTF), and myosin, but not desmin. No expression of the TSC2 gene product, tuberin, was seen in three cases. One case studied cytogenetically disclosed a t(3;10). Follow-up data, available in six of seven cases (median duration, 18 mos), showed five patients to be free of disease and one to have a radiographically presumed lung metastasis. We think these tumors comprise a new entity for which we propose the term "clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres." The differential diagnosis of these tumors includes clear cell sarcoma of tendons and aponeuroses, leiomyosarcoma, and angiomyolipoma.

Abdominal Neoplasms↗

PubMed2000

Low-grade fibromyxoid sarcoma and hyalinizing spindle cell tumor with giant rosettes: a clinicopathologic study of 73 cases supporting their identity and assessing the impact of high-grade areas.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma characterized by bland histologic features and a paradoxically aggressive clinical course. The hyalinizing spindle cell tumor with giant rosettes (HSCT) is a closely related tumor characterized by the presence of giant collagen rosettes. Only a single example of a metastasizing HSCT has been reported. A small subset of both LGFMS and HSCT display areas of increased cellularity and atypia which qualify as intermediate- to high-grade sarcoma; the significance of these features has not been definitively assessed. We present the clinicopathologic features of 77 cases of LGFMS and HSCT to determine the degree of overlap of these two lesions, their biologic behavior, and the significance of the occasional presence of intermediate- to high-grade sarcoma within both. The patients (33 female, 40 male) ranged from 3 to 78 years of age (median, 34 yrs). Fourteen cases occurred in patients less than 18 years of age. The tumors measured from 1 to 23 cm (median, 4.5 cm) and occurred predominantly in the trunk and lower extremities in both the deep (66 cases) and superficial (7 cases) soft tissues. In 15 cases, the tumor was present > 1 year before diagnosis. All tumors showed predominantly the typical hypocellularity and bland cytologic features of typical LGFMS; however, areas of hypercellularity and nuclear enlargement and hyperchromatism were identified in 12 of 73 (16%) and 7 of 73 (10%), respectively. Necrosis and mitotic activity >5/50 high-powered fields (HPF) were present in 6 of 73 (8%) and 5 of 73 (7%), respectively. Epithelioid areas were present in 33 of 73 (45%) and rosettes in 22 of 73 (30%). Follow up (54 cases; range, 2-192 mos; median, 24 mos; mean, 38 mos) showed 5 recurrences, 3 metastases, and 1 death. The diagnosis of LGFMS or HSCT was made prospectively in 51 patients; none had metastatic disease. Two of the metastatic tumors were LGFMS and one was a HSCT. LGFMS may occur more often in the pediatric population and show a much wider histologic spectrum than previously thought. A significant number of LGFMS possess inconspicuous collagen rosettes characteristic of HSCT, indicating that these two tumors are ends of a common spectrum rather than distinct entities. HSCT, like LGFMS, are low-grade sarcomas with metastatic potential. The presence of focal areas of intermediate- to high-grade sarcoma does not portend a worse outcome in the short term. The better prognosis reflected in this study compared with previous ones might reflect the fact that all were initially diagnosed as sarcomas and treated with aggressive surgery. The fact that the only three patients to develop metastatic disease were patients whose LGFMS or HSCT was identified retrospectively supports this concept.

Adolescent↗

PubMed2000

Immunohistochemical detection of FLI-1 protein expression: a study of 132 round cell tumors with emphasis on CD99-positive mimics of Ewing's sarcoma/primitive neuroectodermal tumor.

The histologic and immunohistochemical differentiation of Ewing' s sarcoma/primitive neuroectodermal tumor (ES/PNET) from other small, blue, round cell tumors may be difficult. Despite initial promise, CD99 (MIC2) has not proven to be a specific marker. Approximately 90% of ES/PNET have a specific t(11; 22)(q24;q12) that results in fusion of the EWS and FLI-1 genes, and overexpression of FLI-1 protein. A recent study has shown immunohistochemical FLI-1 expression in five of seven of the ES/PNET cases tested. We evaluated FLI-1 expression in 132 well-characterized small, blue, round cell tumors. All tumors were immunostained for FLI-1 (1:40, Sc 356 polyclonal, Santa Cruz Biotechnology) using steam heat for epitope retrieval. Only nuclear staining was accepted as positive. Endothelial cells were strongly positive in all cases and served as an internal control. In many cases, a subset of lymphocytes also stained positive. No staining was seen in any other normal tissue. FLI-1 expression was seen in 29 of 41 (71%) ES/PNET, 7 of 8 (88%) lymphoblastic lymphomas, 0 of 8 poorly differentiated synovial sarcomas (PDSS), 0 of 32 rhabdomyosarcoma (RMS), 0 of 30 neuroblastomas, 0 of 8 esthesioneuroblastomas, 0 of 3 Wilms' tumors, 0 of 1 mesenchymal chondrosarcoma, and in 1 of 1 desmoplastic round cell tumor. This last case was known to have an EWS/WT-1 fusion. Although the EWS/FLI-1 fusion gene is specific for ES/PNET, FLI-1 protein expression is not. Significantly, the great majority of lymphoblastic lymphomas (also CD99-positive) are strongly FLI-1-positive. Immunohistochemical detection of FLI-1 may be valuable in confirming the diagnosis of ES/ PNET in cases in which molecular genetic evaluation is not feasible. FLI-1 protein expression is also helpful in distinguishing ES/PNET from other tumors that may be CD99-positive, such as PDSS and RMS. It is not surprising that some ES/ PNET are FLI-1-negative, because not all ES/PNET have the classic EWS/FLI-1, and some cases of ES/PNET may produce either low levels of protein or idiotypically different protein.

12E7 Antigen↗

PubMed2000

Paratesticular soft tissue neoplasms.

Paratesticular soft tissue tumors are uncommon neoplasms that may present significant challenges for the pathologist and clinician. This article reviews the incidence of these rare tumors, and on the common benign and malignant entities that occur in this location. Key points in differential diagnosis are emphasized. The grading, staging, and management of patients with paratesticular sarcomas is also discussed.

Canada↗

PubMed1999

Immunohistochemical localization of N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor subunits in the substantia nigra pars compacta of the rat.

Ionotropic glutamate receptors in the substantia nigra pars compacta regulate the activity of dopamine neurons. We have used dual-label immunofluoresence and confocal laser microscopy to study the localization of subunits of two types of ionotropic receptors within the substantia nigra pars compacta of the rat. Immunostaining for N-methyl-D-aspartate receptor 1 and glutamate receptor 2/3 was prominent in the soma and proximal dendrites of all tyrosine hydroxylase-immunopositive cells, while only low amounts of N-methyl-D-aspartate receptor 2A and N-methyl-D-aspartate receptor 2B were present. Selective antibodies were used to determine the isoforms of N-methyl-D-aspartate receptor 1 present. Immunostaining for the N1, C1 and C2 variably spliced segments of N-methyl-D-aspartate receptor 1 were scarce in the substantia nigra pars compacta, while immunoreactivity for the alternative C2' terminus of N-methyl-D-aspartate receptor 1 was quite abundant. Staining for glutamate receptor 1 was heterogeneous; about half of the tyrosine hydroxylase immunopositive cells stained intensely, while the other half were immunonegative. The glutamate receptor 1-stained cells were concentrated in the ventral tier of the substantia nigra pars compacta. Glutamate receptor 4 was not found in tyrosine hydroxylase-immunopositive cells within the substantia nigra pars compacta. Together, these data demonstrate that dopaminergic neurons in the substantia nigra pars compacta express primarily glutamate receptor 1, glutamate receptor 2/3 and N-methyl-D-aspartate receptor 1 isoforms containing the alternative C2' terminus.

Animals↗

PubMed1999

Stromal tumors of the abdominal colon: a clinicopathologic study of 20 cases.

Stromal tumors of the abdominal colon, the least common of all gastrointestinal stromal tumors, have not been well characterized. They have often been lumped with stromal tumors of the anorectum in order to achieve significant numbers for analysis, yet there are no data to prove that stromal tumors from these two sites are the same. In this study, we evaluated 20 colonic stromal tumors to identify clinical, morphologic, and immunophenotypic features that were useful in discriminating between those that had metastasized or caused death from those that had not metastasized or caused death. We found that colonic stromal tumors are morphologically heterogeneous, and the malignant ones are clinically aggressive. They often have metastases at presentation, and cause death in a short time. An infiltrative growth pattern in the muscularis propria, invasion of the mucosa, and high mitotic counts correlated significantly both with metastases and with death from tumor. We also found that dense cellularity correlated significantly with metastases, but not with death, and that coagulative necrosis correlated with death, but not with metastases.

Adult↗

PubMed1999

Stromal tumors of the anorectum: a clinicopathologic study of 22 cases.

Stromal tumors of the anorectum are a rare group of mesenchymal tumors that often have a protracted clinical course. We sought to determine which clinical, morphologic, and immunophenotypic features correlated with an adverse outcome in 22 patients with anorectal stromal tumors. An adverse outcome, defined as either tumor recurrence or metastasis, occurred in nine patients. Seven patients had metastases, two of whom also had local recurrences. Four of these patients also died from their disease. One patient had one local recurrence, and one patient had two local recurrences; neither of these patients had metastases. Recurrences were found as long as 103 months and metastases as late as 117 months after initial presentation. However, for patients without an adverse outcome, maximum follow-up was only 84 months. Thus both recurrence and metastasis may not appear until several years after treatment, indicating that a long-term follow-up period, probably longer than available for many tumors without an adverse outcome in this study, is needed before a patient can be considered to be cured. Tumor size greater than five centimeters correlated with an adverse outcome. However, given the protracted course of these tumors and the relatively limited follow-up available, other features such as location within the muscularis propria, mitotic activity, necrosis, and pleomorphism that did not significantly correlate with an adverse outcome may become significant with longer follow-up periods. We also found that on the basis of morphologic appearance and whether tumors were confined to the submucosa or located within the muscularis propria, anorectal stromal tumors could be divided into three groups, and that the behavior of anorectal stromal tumors may also depend upon their phenotype. The largest group of 17 tumors was located within the muscularis propria, mitotically active, and composed of densely cellular spindle-shaped cells. A second group of two tumors was also located within the muscularis propria and was composed of spindle-shaped cells, but lacked dense cellularity and mitotic activity. The third group was composed of three submucosal, polypoid tumors.

Adult↗

PubMed1999

Parachordoma is immunohistochemically and cytogenetically distinct from axial chordoma and extraskeletal myxoid chondrosarcoma.

Parachordoma is a rare soft-tissue tumor resembling extraskeletal myxoid chondrosarcoma and chordoma. Because fewer than 30 cases have been reported and precisely characterized, we studied the clinicopathologic features of seven new cases, comparing the immunohistochemical (six cases) and cytogenetic (one case) profiles with 15 cases of chordoma and six cases of extraskeletal myxoid chondrosarcoma. Patients with these tumors ranged in age from 7 to 62 years (mean, 35 years) and included four women and three men. The tumors presented as subfascial masses of the thigh (two cases), arm (three cases), chest wall (one cases), and buttocks (one case). In six of seven cases, there was neither recurrence nor metastasis within the follow-up, which ranged from 4 months to 7 years. The tumors were composed of vague nodules of large, rounded eosinophilic cells embedded in a matrix that varied from myxoid to densely hyaline, and the latter areas occasionally resembled primitive cartilage. Transitions between the large eosinophilic cells and smaller rounded and shorter spindled ones were often noted. Multivacuolated (physaliferouslike) cells were noted in all cases but were usually few in number. The matrix stained with Alcian blue (pH 2.5), and this staining was abolished with hyaluronidase predigestion. Immunohistochemistry for a variety of cytokeratins (CKs) (8/18, 1/10, 7, and 20), epithelial membrane antigen (EMA), S-100 protein, vimentin CD34, type IV collagen, smooth muscle actin, smooth muscle myosin heavy chain, calponin, and glial fibrillary acid protein was performed. All parachordomas strongly expressed CK 8/18, but not the other cytokeratins. Additionally, they expressed EMA (five of six). S-100 protein (six of six), and vimentin (six of six) and had a linear pattern of type IV collagen immunoreactivity around nests of cells (four of five). Calponin was noted in one case, but no cases expressed smooth muscle actin, smooth muscle myosin heavy chain, or glial fibrillary acid protein. In contrast, chordoma expressed CK 8/18 (15 of 15) and CK 1/10 (14 of 15), whereas extraskeletal myxoid chondrosarcoma consistently lacked CK. Although chordoma and extraskeletal myxoid chondrosarcoma showed considerable overlap with parachordoma, with respect to EMA and S-100 protein, they infrequently displayed type IV collagen, as was seen in parachordoma. One case of parachordoma studied cytogenetically disclosed trisomy 15, and monosomies of 1, 16, and 17 in contrast to the t(9;22) reported in extraskeletal myxoid chondrosarcoma and the monosomies of 3, 4, 10, and 13 seen in chordoma. We conclude that the immunohistochemical and cytogenetic profile distinguishes parachordoma from extraskeletal myxoid chondrosarcoma and chordoma. Lack of myoepithelial markers, furthermore, suggests parachordoma is not a deeply situated adnexal tumor. Because of these differences, parachordoma is best regarded as a distinct lesion without a clear relationship to other well-characterized tumors.

Adolescent↗

PubMed1999

Lipomatous hemangiopericytoma: a rare variant of hemangiopericytoma that may be confused with liposarcoma.

We describe the clinicopathologic features and biologic behavior of 16 cases of histologically benign hemangiopericytoma containing a variable amount of mature fat as an intrinsic part of the neoplasm. These so-called lipomatous hemangiopericytomas occurred primarily in men (12 men and 4 women) with a mean age of 54 years (range, 33-74 years). All occurred in deep soft tissue and had an average size of 10 cm when first detected. All were characterized by a relatively sharp border and typical histologic features of hemangiopericytomas, including oval to round cells surrounding a sinusoidal and staghorn vasculature often with perivascular hyalinization. Mature fat varied in amount but usually occupied approximately one quarter to three quarters of the area of tumor. Mitotic activity was low, with more than half the cases having no mitotic activity. Five cases showed moderate nuclear atypia. In four cases, the pericytic regions had sclerotic zones. In contrast to liposarcoma, neither lipoblasts nor isolated atypical hyperchromatic cells within mature fat, as are seen in well-differentiated liposarcoma, were present. Immunohistochemistry performed in four cases showed factor XIIIa in tumor cells and an intricate pattern of immunoreactivity around cells for type IV collagen. CD34 and smooth-muscle actins were identified in two of four cases. Follow-up in seven cases showed no recurrences or metastases within the follow-up period of 1 to 7 years. Because these lesions are located in deep soft tissue and contain large amounts of mature fat, they could be mistaken for well-differentiated liposarcomas in limited biopsy material, although the distinction is easily made in examining the entire specimen. The lipomatous hemangiopericytoma represents yet another example of a bimodal mesenchymal tumor containing mature fat and raises the question of whether a common cytogenetic abnormality can explain the emergence of two clonal populations in this hybrid tumor.

Adult↗

PubMed1999

Soft tissue giant cell tumor of low malignant potential: a proposal for the reclassification of malignant giant cell tumor of soft parts.

Although "giant cell tumor of soft parts" has traditionally been considered a single entity as reflected in the original term "malignant giant cell tumor of soft parts (MGCT)" and later by the term "malignant fibrous histiocytoma, giant cell type" the degree of atypia and mitotic activity varies in this group, suggesting biologic heterogeneity. The clinicopathologic features of 31 tumors meeting the traditional criteria of MGCT but having only mild to moderate nuclear atypia are presented. Patients with these tumors (19 females; 12 males) ranged in age from 14 to 84 years (mean, 40 years) and presented with masses of involving either superficial (n = 16) or deep (n = 13) soft tissue. Most occurred on the arm or hand (n = 16) and ranged in size from 0.7 to 6.5 cm (mean, 2.1 cm). The tumors consisted of sheets and nodules of rounded mononuclear cells that blended with spindled cells and benign osteoclastic giant cells. Pleomorphic giant cells were absent. Osteoid was noted in 10 cases, but features typically associated with tenosynovial giant cell tumors (such as dense stromal hyaline, siderophages, and xanthoma cells) were nearly always absent. Mitotic figures ranged from 1-10/10 HPF (mean, 2-3/10 high-powered field), and angiolymphatic invasion was present in 10 cases. Necrosis was absent, however. The mononuclear cells expressed CD68, tartrate-resistant acid phosphatase, and smooth muscle actin, but lacked CD45, S100 protein, desmin, and lysozyme, an immunophenotypic profile identical to that of giant cell tumor of bone. Follow-up information in 19 patients (mean, 3 yrs; median, 1-7 yrs) indicated recurrences in four patients, but none developed metastasis. This behavior contrasts significantly with the high-grade behavior traditionally associated with MGCT of soft parts. These giant cell tumors can be consistently recognized by the lack of cytologic atypia even in the face of mitotic activity and vascular invasion. Although their long term metastatic risk is not fully defined, we propose they be termed "giant cell tumors of low malignant potential" and regarded as the soft tissue analogue of giant cell tumor of bone. The term "malignant giant cell tumor of soft parts" or giant cell malignant fibrous histiocytoma should be restricted to histologically high-grade lesions.

Acid Phosphatase↗

PubMed1998

NMDAR1 glutamate receptor subunit isoforms in neostriatal, neocortical, and hippocampal nitric oxide synthase neurons.

Nitric oxide (NO), an unconventional and diffusible neurotransmitter, is synthesized by nitric oxide synthase (NOS). NMDA glutamate receptors are potent regulators of NO synthesis. We have used dual-label immunofluorescence and confocal microscopy to examine forebrain neurons in the rat that contain high levels of neuronal NOS (nNOS) for the presence of the NMDAR1 receptor subunit protein and regions of this protein encoded by three alternative spliced segments of the NMDAR1 mRNA: N1, C1, and C2. In the neostriatum, neocortex, and hippocampus, nNOS-labeled neurons exhibit strong NMDAR1 immunoreactivity (-ir). In all three of these regions, nNOS-positive neurons are characterized by the absence of immunoreactivity for the C1 segment of NMDAR1, whereas C1-ir is abundant in most nNOS-negative neurons. In addition, nNOS-ir neurons exhibit selective staining for the alternative C2' terminus of NMDAR1 that is produced when the C2 segment is absent. These results demonstrate directly that neurons with abundant nNOS-ir contain NMDAR1 receptor subunit proteins and that the NMDAR1 isoforms present in these cells differ from those of most other neurons in these regions. The distinct NMDA receptor phenotype of these nNOS-positive neurons is likely to contribute to both the physiological regulation of NO release by glutamate as well as to NO-mediated excitotoxic injury.

Animals↗

PubMed1998

Immunohistochemical localization of metabotropic glutamate receptors mGluR1a and mGluR2/3 in the rat basal ganglia.

Metabotropic glutamate receptors (mGluRs), which couple glutamate to second messengers, have important roles in the regulation of movement by the basal ganglia. We used two polyclonal antisera to mGluR1a and mGluR2/3 and confocal laser microscopy to investigate the localization of these receptors in the basal ganglia of the rat. The mGluRs were visualized in combination with an antibody to tyrosine hydroxylase (TH), an antibody to microtubule-associated protein 2 (MAP2, a dendritic marker), or SV2 (an antibody to a protein associated with presynaptic terminals). In the neostriatum, punctate mGluR1a immunoreactivity (ir) was present in the neuropil. This staining did not colocalize with MAP2-ir or SV2-ir and was not altered by decortication or unilateral 6-hydroxydopamine (6-OHDA) lesions. In the globus pallidus and substantia nigra pars reticulata, however, mGluR1a-ir was tightly clustered along large MAP2-ir dendrites. In contrast to the variations in mGluR1a-ir staining, similar punctate neuropil mGluR2/3-ir staining was observed within all basal ganglia structures. In the neostriatum, these puncta were abundant; unlike mGluR1a, many mGluR2/3-ir puncta colocalized with SV2-ir, and striatal mGluR2/3-ir puncta were markedly reduced in number after decortication. Neither mGluR1a-ir nor mGluR2/3-ir could be detected in TH-ir soma within substantia nigra pars compacta, or in TH-ir striatal terminals. Overall, our observations suggest that mGluR1a and mGluR2/3 receptors have distinct cellular localizations in different components of the basal ganglia circuitry and are likely to subserve distinct functions. Our data support the presence of mGluR2/3 on the terminals of corticostriatal afferents, where they may regulate glutamate release. In contrast, mGluR1a appears to be a postsynaptic receptor of neurons in the neostriatum, globus pallidus, and substantia nigra pars reticulata.

Animals↗

PubMed1998

Allelic loss on chromosome 22q in epithelioid sarcomas.

Epithelioid sarcomas are soft tissue tumors with an indolent, but potentially aggressive, clinical behavior. Distinction from other benign and malignant entities may be a diagnostic dilemma. In this study, we evaluate the presence of loss of heterozygosity (LOH) of chromosome 22q in tumor DNA from 13 epithelioid sarcomas, four epithelioid angiosarcomas, and two epithelioid hemangioendotheliomas, and investigate its possible role in diagnosis. LOH was detected in 6 of 10 (60%) of the informative epithelioid sarcomas. No allele loss was detected in the informative vascular tumors, three angiosarcomas, and two hemangioendotheliomas. Chromosome 22q carries the locus of a tumor suppressor gene, the neurofibromatosis 2 (NF2) gene, which has been shown to be lost or mutated in some NF2-related tumors, sporadic meningiomas, and vestibular schwannomas, as well as a few other tumors. Our data suggest that a region of chromosome 22q may be the locus of a tumor suppressor gene involved in the tumorigenesis of these neoplasms. Genetic alterations of yet-unknown tumor suppressor genes in this region, or even the NF2 tumor suppressor gene, may play a role in epithelioid sarcomas tumorigenesis. The fact that LOH was only detected in epithelioid sarcomas and not in the vascular tumors studied suggests a possible role for this marker in diagnosis.

Adolescent↗

PubMed1998

Multiple spindle cell lipomas: a report of 7 familial and 11 nonfamilial cases.

Spindle cell lipoma, a variant of a benign lipoma, usually occurs as a solitary, subcutaneous, circumscribed lesion in the posterior back, neck, or shoulders of older men. Multiple lesions are exceedingly rare. To our knowledge, there have been no previous series reported of patients with multiple subcutaneous spindle cell lipomas. We examine the clinicopathologic findings of a group of patients with multiple spindle cell lipomas, including seven with a familial occurrence of this disease. The Soft Tissue Registry of the Armed Forces Institute of Pathology and the consultation files of one of the authors (S.W.W.) from the Department of Pathology at the University of Michigan were searched for patients with multiple spindle cell lipomas. All patients' records, clinical history, and pathology were reviewed. All patients had a minimum of two tumors that met strict morphologic criteria for spindle cell lipoma. Pleomorphic cells, typical of pleomorphic lipoma, were observed in some cases and were acceptable as part of the spectrum of spindle cell lipomas. Associated lesions, family history, ethnic background, daily habits, and natural progression of disease were recorded and compared. Eighteen patients in our files met the criteria for multiple spindle cell lipomas; 4 of the 18 patients were from the same family. Three additional patients had a family history of multiple spindle cell lipomas. The ratio of patients with multiple spindle cell lipomas to all patients with spindle cell lipoma in the two consultation files was 0.5 and 3%, respectively. All of the patients in our study were male; three had a family history of females with less severe disease (fewer and smaller spindle cell lipomas); however, no material from these female patients was available for review. All but four patients presented in their sixth through eighth decades of life; yet, several older patients stated that their first lesion occurred in their fifth decade. Patients had between 2 and >220 lesions, which usually commenced on the posterior neck or back, commonly followed by additional bilateral lesions on the shoulders and upper torso. The natural history of this disease revealed development of multicentric lesions over several years, for both familial and nonfamilial cases. The tumors became more cellular as the disease progressed, often with features of pleomorphic lipoma; however, no patients developed spindle cell liposarcoma. Multiple spindle cell lipomas are rare. The clinical presentation may mimic Madelung's disease (symmetrical lipomatosis). As mentioned above, some cases are familial. Genetic predisposition must be further examined. There appears to be no common ethnic background, environmental exposure, medical condition, or syndrome of associated lesions with multiple spindle cell lipomas.

Adult↗

PubMed1998

Massive localized lymphedema in the morbidly obese: a histologically distinct reactive lesion simulating liposarcoma.

We report 14 cases of a soft tissue lesion in the limbs of morbidly obese adults that presents as a large mass and histologically simulates well-differentiated liposarcoma (WDL). Based on its distinctive clinical setting and morphologic identity to diffuse lymphedema we have termed this process massive localized lymphedema (MLL). All cases occurred in morbidly obese adults (mean weight 372 lbs; mean age 47 years). Women predominated (9 women; 5 men). The lesions affected the proximal medial aspect of the extremities (12 thigh; 2 arm) and were unilateral in all but two patients. Etiologically significant antecedent events include ipsilateral axillary lymphadenectomy in both patients with arm lesions, chronic lymphedema resulting from vein-stripping 10 years prior in one patient. inguinal lymphadenectomy for anal carcinoma in another patient, and significant blunt trauma to the inner thigh during a motor vehicle accident in a third patient. The tumors were long standing ( I-IO years) and extremely large (mean size 33.4 cm, 7408 g). Clinically, they were diffuse, ill-defined masses that histologically consisted of lobules of mature fat interrupted by expanded connective tissue septa. The constituents of the septa were fine, fibrillary collagen, edema fluid, and uniformly distributed fibroblasts. Clusters of capillaries were frequently found at the interface between fat and connective tissue. The widened septa simulated the fibrous bands of sclerosing WDL, but MLL lacks the degree of nuclear atypia seen in the former. The consistent clustering of reactive vessels at the interface between the fat and fibrous tissue also contrasted with WDL. Six patients experienced persistent or recurrent lesions within 10 months to 10 years. No aggressive growth or histologic progression was observed during this time, however. Awareness of the features of MLL is important to avoid misclassification of this reactive lesion with WDL.

Adipose Tissue↗

PubMed1998

Liposarcoma: an update.

Liposarcoma is one of the most common adult soft tissue sarcomas. It is best viewed as several related tumors rather than a common one, however. Support for this is derived from the fact that the various subtypes differ in their demographic, cytogenetic, and biologic properties. The pathologist, therefore, assumes a pivotal role in accurately classifying these lesions since this directly translates into grade and behavior. As the molecular events leading to these tumors are better understood, our approach to treating the various forms of liposarcoma may, likewise, differ.

Adult↗