Biomedical subjects
Publications and source records attributed to P Abenoza.
Inflammatory pseudotumor is a tumoral non-neoplastic lesion of unknown etiology that has been described in several locations. We report the histopathological and immunohistochemical findings of this lesion in the cervix of a 58-year-old woman whose main complaint was pelvic pain.
To assess the use of anti-CD34 and anti-factor-XIIIa antibodies for the differential diagnosis of dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP), we stained 40 DFs and 13 DFSPs. A significant population of dendritic and spindle cells was reactive with anti-factor-XIIIa in 90% of DFs. In DFSP, most cases had very few or no reactive cells for this antiserum and reactivity was confined to the infiltrating edges of the neoplasm or to a very low percentage of cells within the bulk of the tumor. A significant overlap was detected, a reason why the stain is useful but lacks absolute specificity for this purpose. Human progenitor cell antigen (CD34) was found in all cases of DFSP that had 50-100% of reactive cells, but in only five DFs. In DFs, the reactivity for CD34 was focal, with only < or = 20% positive cells. When used together with other histopathological criteria, factor-XIIIa antibody and particularly CD34 may help to differentiate these two processes.
We describe a case of mucinous syringometaplasia in a 53-year-old man. The lesion was located on a previously unreported site, the shaft of the penis. Histologically the lesion contained bland mucinous cells in acrosyringia that extended to the adjacent epidermis. A review of previously reported cases is provided. Even though the name given to this entity implies a reactive nonneoplastic condition, the possibility that this is a benign intraepithelial mucinous neoplasm has not been ruled out. The main differential diagnosis is with extramammary Paget's disease.
We describe the clinical, structural, and immunophenotypic characteristics of a lymphoproliferative process characterized by persistent thrombocytopenia and prominent involvement of the spleen and, to a lesser degree, the liver. The proliferating cells lacked cytoplasmic azurophilic granules by light microscopy and on ultrastructural examination displayed prominent interdigitating cell processes and did not contain parallel tubular arrays. Immunophenotypically, the cells displayed markers of true natural killer cells (positive CD2, CD56, CD45, CD7, CD16, and CD33). No involvement of peripheral blood or bone marrow was detected. This case represents a proliferation of true natural killer cells probably arising in the spleen. The relationship of this process to other lymphoid proliferations at different sites with true natural killer cell or natural killer-like activity is unknown.
Magnetic resonance (MR) images of 16 peripheral nerve tumors (14 patients) were correlated with histopathologic appearance. Thirteen patients had surgically proved neuro-fibromatosis. There were 10 neurofibromas, four schwannomas, and two neurofibrosarcomas. Seven of the 10 neurofibromas showed a target pattern of increased peripheral signal intensity and decreased central signal intensity on T2-weighted images. This pattern appeared to correspond to a distinctive zonal histologic appearance that was found only in the neurofibromas. This pattern was not seen on MR images of the other peripheral tumors.
The clinicopathologic and immunohistochemical features of 16 pure adenocarcinomas primary in the urinary bladder were reviewed. Only 3 patients were found to have disease confined to the urinary bladder. Of 13 cases with follow-up only 3 are free of disease. Histologically, the tumors were classified as signet ring cell (3), colloid (3), colonic type (5), clear cell (1), and not otherwise specified (NOS, 4). Immunohistochemically, all tumors but one colloid carcinoma were immunoreactive for cytokeratin and epithelial membrane antigen, and most tumors were likewise immunoreactive for carcinoembryonic antigen. Eight cases were immunoreactive for Leu M1 antigen. Prostate specific antigen, S-100 protein, and placental alkaline phosphatase were uniformly negative. No correlation between immunohistochemical profile and histologic type or clinical outcome was found. The utility of immunohistochemistry and other pathologic findings is reviewed.
The ultrastructural and immunohistochemical features of 19 hepatoblastomas were examined to evaluate the phenotypic expressivity of this solid embryonic neoplasm of childhood. Electron microscopy confirmed the embryonal and fetal characteristics of the neoplastic hepatocytes, but in addition, cells with features intermediate between these two cell types were identified. Dense bundles of collagen corresponding to the osteoid-like material by light microscopy surrounded nests of cells; the cells within this matrix stained for epithelial membrane antigen and vimentin and focally for cytokeratin, and they showed ultrastructural features of epithelial cells. The two cases of small cell hepatoblastoma reacted positively for vimentin and cytokeratin; the remaining 17 cases were immunoreactive for cytokeratin and alpha-fetoprotein, and some also for alpha 1-antitrypsin, ferritin, and vimentin. A histogenetic scheme based on our findings is proposed to explain the divergent morphologic features of this neoplasm.
We present the histological, ultrastructural, and immunohistochemical findings of two granular cell tumors of different histogenesis: a mediastinal granular cell schwannoma, and an uterine granular cell leiomyoma. Ultrastructurally the mediastinal tumor showed granular cell changes of the Schwann cells which were reactive for S-100 protein and Leu 7 antigen, but not for actin, desmin, CEA, EMA, or cytokeratin. Ultrastructural study of the uterine lesion demonstrated smooth muscle cells with only a few "autophagic" facuoles to cells nearly replaced by lysosomes. Immunohistochemically this tumor showed reactivity for actin, desmin, and Leu 7 antigen, but was S-100 protein, CEA, EMA, and cytokeratin negative.
A 1-week-old baby boy presented with hepatosplenomegaly, coarse facial features, and cloudy corneas. A metabolic storage disease was considered and he underwent cutaneous and liver biopsy. By light microscopy the skin was normal. Kupffer cells were enlarged and had foamy cytoplasm. Ultrastructural examination of skin and liver demonstrated features compatible with Farber's disease: curvilinear and "banana" bodies, zebra-like structures, and concentric lamellar bodies. A deficiency of lysosomal acid ceramidase was subsequently demonstrated in cultured fibroblasts and in liver tissue corroborating the ultrastructural findings.
The presence of divergent tissue, such as bone or osteoid, is a well recognized occurrence in the hepatoblastoma. However, multiple lines of tissue differentiation in a hepatic tumor that had the overall features of hepatoblastoma have recently been observed. During the brief and eventually fatal clinical course in this case, the tumor initially displayed the features of conventional hepatoblastoma, but evolved into a neoplasm with teratoid features, terminally assuming a hepatoma-like appearance. Immunohistochemistry and ultrastructural studies confirmed the various lines of divergent differentiation in this tumor, which the authors chose to designate as a teratoid hepatoblastoma.
Fourteen chordomas, five myxoid chondrosarcomas, and 15 chondroid tumors (four mesenchymal and 11 conventional chondrosarcomas) were stained for cytokeratin, S-100 protein, carcinoembryonic antigen (CEA), and vimentin. The epithelial markers stained 93 per cent of the chordomas, whereas none of the tumors of other types showed any staining. Sixty-four per cent of the chordomas, 20 per cent of the myxoid chondrosarcomas, and 87 per cent of the other chondroid tumors were positive for S-100 protein. All of the tumors were positive for vimentin. Three of the 14 chordomas were positive for CEA. The present study confirms the utility of these markers in the differential diagnosis of chordoma and tumors with similar histologic characteristics.
To analyze the purportedly epithelial features of synovial sarcoma, the antigenic profiles of 20 of these neoplasms (including 12 of the monophasic type) were studied by three different immunohistochemical techniques, and the results were correlated with ultrastructural observations in 10 cases. All of the biphasic tumors were immunoreactive for the epithelial markers epithelial membrane antigen (EMA) and cytokeratin (CK) and also had ultrastructural features of epithelial differentiation. In contrast, only one of five monophasic tumors had electron microscopic features suggestive of epithelial differentiation, but eight of the 12 were immunoreactive for CK or EMA by a procedure combining the peroxidase-antiperoxidase and avidin-biotin-peroxidase complex methods. It is concluded that synovial sarcoma, including the monophasic variant, is a mesenchymal tumor with epithelial features. Immunohistochemical studies are more sensitive than ultrastructural analysis for documenting epithelial differentiation.
The occurrence of a sarcomatous component in germ cell tumors is an uncommon phenomenon; seven cases with such an association are presented. The sarcomatous elements were rhabdomyosarcomatous in four cases, angiosarcomatous in two, and a combination of these two types in one case. Immunohistochemical studies supported the endothelial and skeletal muscle differentiation of the sarcomatous components. All patients were treated surgically, and some received various chemotherapeutic agents and radiation. On follow-up, four patients had died of their disease, one developed recurrence and pulmonary metastases, one was free of disease after 4 years, and one is a recent case. Chemotherapy protocols may need to be altered to include sarcoma-oriented drugs for this particular group of patients.
The clinicopathologic features of two cases of dedifferentiated chondrosarcoma (DCS) are presented, in which anaplastic components showed the electron microscopic features of malignant fibrous histiocytoma, as well as immunoreactivity for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Rare cells also displayed S100 protein in high-grade areas of the primary tumors, but a pulmonary metastasis lacked this determinant. These findings could be interpreted as reflecting a retained potential for primitive chondrogenesis in primary DCS, which may be lost in its metastases. In all other respects, this tumor appears to assume the morphological and immunocytochemical attributes of a fibrohistiocytic neoplasm.
A case is presented of a primitive neuroectodermal tumor located in the left frontal cerebrum, which demonstrated electron microscopic and immunocytochemical evidence of rhabdomyoblastic differentiation. Within the group of supratentorial primitive neuroectodermal tumors, only medulloepithelioma has previously been shown to manifest "divergent" differentiation. In several respects our case is analogous to infratentorial "medullomyoblastoma."
We report the case of a 14-year-old girl with a left atrial myxoma associated with atrial septal defect. Histopathologically, glandular structures were found at the base of the tumor. Immunohistochemical examination of the tumor revealed positive staining of the glands with cytokeratin, epithelial membrane antigen, and carcinoembryonic antigen. The positive staining for epithelial markers suggests that these structures are epithelial and could represent either endodermal heterotopia or multipotential mesoderm retaining the capacity for epithelial expression. The glands should not be confused with metastatic mucin-producing adenocarcinoma.
We describe a primary mixed adenocarcinoma-neuroendocrine carcinoma of the urinary bladder of probable urachal origin. Neuroendocrine differentiation was confirmed by ultrastructural (neurosecretory granules) and immunohistochemical studies (chromogranin and neuron-specific enolase). Two local recurrences and multiple metastases consisted exclusively of the neuroendocrine component. The patient died 30 months after diagnosis with widely metastatic neuroendocrine carcinoma.
With the use of a murine monoclonal antibody (F5), a panel of metastatic tumors was evaluated for the expression of prostate-specific antigen (PA) under immunoperoxidase staining procedures. Specimens studied included 25 of prostatic origin and 73 originating from nonprostatic primary sites. Regardless of the site of dissemination or the malignancy grade, all metastases from the prostate were antibody-reactive. In contrast, nonprostatic metastases were negative in each case, including those originating from other genitourinary neoplasms. Thus, PA expression as detected with monoclonal antibody F5 is a stable characteristic of disseminated prostatic tumors.