Search PubMed⌕ Search

Biomedical subjects

D J Dabbs

Publications and source records attributed to D J Dabbs.

At least 55 records · Page 3Linked to original sources
PubMed1987

Malignant mixed müllerian tumors. An ultrastructural and immunohistochemical analysis with histogenetic considerations.

In the female genital tract, malignant mixed müllerian tumors (MMTs) are uncommon neoplasms of uncertain histogenesis. We have examined 11 MMTs by both electron microscopy (EM) and immunoperoxidase techniques (IPX). Eight were of endometrial, two were of ovarian, and one of tubal origins. The IPX analysis included monoclonal antibodies to keratin (k) and vimentin (v) and a polyclonal antibody to myoglobin. Carcinomatous elements were always keratin positive (K+) and were focally positive for vimentin in six tumors. Homologous stromal sarcoma cells were vimentin positive (V+) and in three tumors were focally K+. Ultrastructurally, the epithelial cells were not highly differentiated and the sarcomatous elements generally resembled normal proliferative-phase stromal cells. The epithelial and stromal elements were separated by a thin basal lamina that only rarely and focally had discontinuities. No transitional cellular forms were identified. A definite positive myoglobin reaction was seen in two of the four neoplasms in which rhabdomyoblasts were identified by light microscopy. Myofilaments were identified by electron microscope in three neoplasms.

Aged↗
PubMed1987

In-vitro selection of bacteria resistant to the 4-quinolone agents.

The activity of five 4-quinolone agents: norfloxacin, ciprofloxacin, ofloxacin, enoxacin and pefloxacin was tested against 121 distinct clinical bacterial isolates. Ciprofloxacin was the most active agent against Gram-negative bacteria and streptococci and pefloxacin was the most active against staphylococci. By serial sub-culture in sub-inhibitory concentrations of antibiotic we were able to select resistance in almost all Gram-positive and Gram-negative species, with the exception of Escherichia coli. Resistance to norfloxacin was more readily produced than resistance to the other four agents. There was almost complete cross-resistance among the five agents tested. The proportional increases in MIC were higher in Gram-negative than in Gram-positive organisms.

Anti-Bacterial Agents↗
PubMed1986

Chordoma: diagnosis by fine-needle aspiration biopsy with histologic, immunocytochemical, and ultrastructural confirmation.

Five cases of chordoma, diagnosed by fine-needle aspiration (FNA) biopsy, are presented. Four cases were histologically confirmed, and in one, immunocytochemical and ultrastructural studies were performed on both the aspirate and tissue specimen. Four cases presented as sacral masses, while in the fifth case, a destructive lesion of the clivus extended into the soft tissues of the lateral neck. A spectrum of cytomorphologic features was encountered including the presence of abundant microtissue fragments and cells in a dissociate pattern, often with abundant metachromatic extracellular matrix. Stellate and cuboidal cells often contained intracytoplasmic vacuoles of varying sizes. Intranuclear inclusions, mitotic figures, and anisonucleosis were prominent features of several cases. Immunoperoxidase studies on a single case demonstrated cytoplasmic staining for low- and high-molecular-weight cytokeratins, vimentin, and epithelial membrane antigen, while glial fibrillary acidic protein and carcinoembryonic antigen were negative. Ultrastructural features included the presence of mitochondrial endoplasmic reticulum complexes, occasional desmosome-like junctions, and abundant extracellular matrix adherent to the tumor cells. We believe the cytomorphologic findings are characteristic and, when taken in concert with immunocytochemical and ultrastructural studies, allow differentiation of chordoma from other primary or metastatic neoplasms occurring in bone. As demonstrated in our series, chordoma is often an unsuspected diagnosis. We believe that FNA biopsy of these lesions can lead to a correct preoperative diagnosis and may also be utilized to document recurrence and thus facilitate the evaluation and management of patients with these lesions.

Aged↗
PubMed1986

Glomerular lesions in lymphomas and leukemias.

Renal lesions in lymphoid malignancies are rare, with most lesions observed in association with Hodgkin's disease. In two large series of patients with Hodgkin's disease, only 0.4 percent had minimal-change lesion whereas 0.1 percent had amyloidosis. The non-Hodgkin's lymphomas and leukemias comprise large and heterogeneous groups with equally diverse renal lesions. As in Hodgkin's disease, the most frequent lesion is minimal-change nephrotic syndrome. Also recognized are rare reports of renal disease associated with the atypical lymphoid proliferations of angioimmunoblastic lymphadenopathy, giant lymph node hyperplasia syndrome, and acquired immune deficiency syndrome. Broad generalizations regarding the pathogenesis of renal disease in these syndromes are difficult, partly due to the paucity and sporadic reporting of such cases. Mechanisms proposed to explain the renal pathologic findings include autologous nontumor antigens, tumor antigens, fetal antigen expression, immune complex deposition, viral antigens, and disordered T cell function.

Amyloidosis↗
PubMed1986

Localized primary (AL) amyloid tumor of the breast. Cytologic, histologic, immunocytochemical and ultrastructural observations.

Two examples of localized primary amyloid tumor of the breast are presented, including one patient with metachronous bilateral lesions. Our findings and review of the literature indicate that this rare lesion occurs predominantly in elderly females and can be mammographically and clinically confused with carcinoma. Fine-needle aspiration biopsy can be a useful procedure to make a preliminary diagnosis. Congo red staining with prior potassium permanganate incubation confirmed the AL type of amyloid in our two cases; this might be the predominant type in the localized form involving the breast. Immunofluorescence studies demonstrated IgA, with kappa and lambda light-chain deposition within the amyloid foci in one case, and intracytoplasmic IgG with both light chains within plasma cells and amyloid deposits of the second case. Ultrastructural examination of one of the cases showed characteristic findings of straight, nonbranching fibrils of 4-9 nm, diagnostic of amyloid. From our findings and a review of the literature, we conclude that amyloid tumors of the breast can occur in three separate settings: secondary amyloidosis, systemic or multiple myeloma associated amyloidosis, and as a localized primary type having a benign course.

Age Factors↗
PubMed1986

Intermediate filaments in endometrial and endocervical carcinomas. The diagnostic utility of vimentin patterns.

We examined the distribution of high- and low-molecular-weight cytokeratins, vimentin, and carcinoembryonic antigen (CEA) in normal endometrial glands and endocervical glands (20 cases each) and in endometrial and endocervical adenocarcinomas (29 cases and 15 cases respectively). Low- and high-molecular-weight cytokeratin staining was present in normal endometrial and endocervical epithelium and in carcinomas. Coexpression of vimentin and cytokeratin was universally present in normal proliferative endometrial glands, with marked decrease or absence of vimentin staining in secretory phase patterns. Vimentin staining had a perinuclear distribution within the cells, in contrast to the cytokeratins, which stained diffusely. Vimentin was found in only 65% of endometrial adenocarcinomas. Staining was typically focal as well as regional in portions of the tumors. Vimentin was never observed in normal or neoplastic endocervical epithelium. Ultrastructural studies corroborate the perinuclear vimentin immunostaining pattern we observed in endometrial adenocarcinomas. CEA staining results were similar to those previously reported. These data indicate that the presence of vimentin may readily distinguish endometrial from endocervical carcinoma and is diagnostically useful in the study of metastatic adenocarcinomas.

Adenocarcinoma↗
PubMed1984

Superficial spreading malignant melanoma with neurosarcomatous metastasis.

Metastatic malignant melanoma often poses a difficult light and ultrastructural diagnostic challenge. A superficial spreading malignant melanoma without desmoplasia displayed neurosarcomatous light and electron microscopic features in metastatic sites. The ultrastructure displayed some Schwann cell features and strong-S-100 immunostaining. Metastatic melanoma with Schwannian differentiation in metastatic sites without lesional desmoplasia is rare and must be included in the differential diagnosis of spindled neoplasms involving lymph nodes. The evolution of this lesion illustrates the spectrum of melanocytic differentiation, i.e., pigment synthesis, adaptive fibroplasia and Schwannian differentiation.

Adult↗
PubMedDate not supplied

Malignant thymic neoplasms: diagnosis by fine-needle aspiration biopsy with histologic, immunocytochemical, and ultrastructural confirmation.

Two cases of malignant thymic neoplasms diagnosed by transthoracic fine-needle aspiration (FNA) biopsy under fluoroscopic and computerized axial tomography (CT) guidance with histologic, immunocytochemical, and ultrastructural confirmation are presented. The clinical and cytomorphologic features of the first case were typical of a malignant thymoma. A characteristic biphasic cell population of benign epithelial cells and mature lymphocytes was seen in Diff-Quik- and Papanicolaou-stained smears from the anterior mediastinal mass and the paravertebral metastasis and was confirmed by histologic examination. Immunoperoxidase studies for T and B cell subsets demonstrated lymphocytes with the thymic lymphocyte phenotype (Leu 6). Electron microscopic (EM) examination revealed epithelial cells with desmosomal attachments, tonofilaments, and extended cell processes along with mature lymphocytes. FNA biopsy of the second case demonstrated features of a thymic carcinoma. Individually scattered and loosely clustered small groups of markedly anaplastic and pleomorphic large cells were seen both in the Diff-Quik- and Papanicolaou-stained smears. EM performed on the FNA specimen demonstrated the poorly differentiated epithelial nature of the malignancy. The mediastinal mass was partially resected and demonstrated an undifferentiated carcinoma staining positively for low-molecular-weight cytokeratin. Ultrastructure demonstrated cell attachments and relationships consistent with carcinoma. The lack of a lung or other extrapulmonary primary tumor was consistent with a thymic carcinoma. These cases demonstrate the value of performing EM and immunocytochemistry on material obtained by fine-needle aspiration, which can aid in establishing the correct diagnosis and facilitate the clinical management of patients with malignant thymic neoplasms.

Adult↗
PubMedDate not supplied

Squamous cell carcinoma arising in recurrent odontogenic keratocyst: case report and literature review.

BACKGROUND: Keratinizing odontogenic cysts of the mandible commonly have an aggressive clinical course, marked by multiple recurrences. Primary intraosseus carcinoma (PIOC) of the mandible is rare, and when it occurs it is often found to be arising in or closely associated with some type of cystic structure. METHODS: A patient with squamous cell carcinoma arising from an odontogenic keratocyst is studied clinically, radiographically, and pathologically. RESULTS: The patient who was documented to have an odontogenic keratocyst, 1 year later had a squamous carcinoma removed from the recurrent cyst. CONCLUSION: We report the occurrence of squamous cell carcinoma arising from a recurrent odontogenic keratocyst, which has not previously been documented in the literature. The literature on this subject is reviewed.

Animals↗
PubMedDate not supplied

Sclerosing stromal tumor of the ovary: an ultrastructural and immunohistochemical analysis with histogenetic considerations.

Sclerosing stromal tumors are rare, benign ovarian neoplasms of unknown etiology and histogenesis. Three sclerosing stromal tumors were evaluated by immunohistochemistry and electron microscopy and were compared to two thecomas and nonneoplastic ovarian mesenchymal tissue. The sclerosing stromal tumors and thecomas were positive for muscle-specific actin; immunoreactivity was intense in the cellular areas of the sclerosing stromal tumors and focal in the thecomas. This antigen was expressed in nonneoplastic stroma predominantly in a perifollicular (theca externa) distribution. Two sclerosing stromal tumors and both thecomas were vimentin positive. Desmin was present in nonvascular cells in one of each tumor type. Expression of vimentin diffusely and of desmin focally was present in nonneoplastic cortical stroma and surrounding follicles. All specimens were nonreactive for cytokeratin. Electron microscopy supported differentiation toward smooth muscle in the sclerosing stromal tumors but not in the thecomas. Such differentiation included aggregates of cytoplasmic filaments with interspersed dense bodies, pinocytotic vesicles, and basal lamina. Delicate, long processes interconnected cells, often with primitive junctions, in the hypocellular foci. Cytoplasmic lipid, which was present in the thecomas, was not well developed in the sclerosing stromal tumors. It is proposed that a population of muscle-specific actin-positive elements exists in the theca externa--the perifollicular myoid stromal cell--and that sclerosing stromal tumors may originate from them. Sclerosing stromal tumors and thecomas share many antigenic determinants and morphologic features and thus are probably closely related entities.

Female↗
PubMedDate not supplied

Cytology of pyelitis glandularis cystica. A case report.

Cytologic findings that occur in association with proliferative lesions involving von Brunn's nests in the urinary tract are rare. Such lesions are probably far more common than recognized and are probably considered in the clinicoradiologic differential diagnosis when space-occupying lesions are found, particularly in the upper urinary tract. Reported here are the cytologic findings in a case of pyelitis glandularis cystica that presented as a renal pelvic lesion.

Cysts↗
PubMedDate not supplied

Fine needle aspiration cytology of perineurioma. Report of a case with histologic, immunohistochemical and ultrastructural studies.

The fine needle aspiration (FNA) findings are presented for a case of perineurioma, a benign soft tissue tumor composed of perineurial cells, which are epithelial-like and ensheath the endoneurial connective tissue space of nerve fibers. A subcutaneous FNA performed on a posterior thigh mass of a 14-month-old boy produced a specimen consisting of numerous spindle-shaped tumor cells with bipolar cytoplasmic extensions and occasional pseudosignet-ring cells in a prominent myxoid background. Cytologically, a diagnosis of benign myxoid tumor was made. Histologic examination of the resected tumor revealed the characteristic features that have been described for perineurioma; the diagnosis was confirmed with immunocytochemical and ultrastructural studies. Perneurioma should be included in the differential diagnosis of benign myxoid neoplasms seen in FNA biopsy specimens.

Biopsy, Needle↗
PubMedDate not supplied

Fine needle aspiration cytology of talc granulomatosis in a peripheral lymph node in a case of suspected intravenous drug abuse.

A fine needle aspiration (FNA) specimen of an epitrochlear lymph node from a 22-year-old suspected intravenous drug abuser was submitted for cytologic examination, which revealed numerous granulomatous tissue fragments, histiocytes, lymphocytes and giant cells. Polarizing microscopy revealed strongly birefringent material of varying shapes and sizes, including anisotropic crystals with the Maltese cross configuration characteristic of starch. A cytologic diagnosis of talc granulomatosis in the lymph node was made. This case emphasizes the value of FNA biopsy in the differentiation of inflammatory versus neoplastic processes; this appears to be the first case of peripheral talc granulomatosis diagnosed by FNA biopsy.

Adult↗
PubMedDate not supplied

Selective use of electron microscopy in fine needle aspiration cytology.

The utility of electron microscopy (EM) applied to fine needle aspiration (FNA) biopsy specimens was analyzed in order to determine the role and the diagnostic contribution of the EM examination. A rapid stain (Diff-Quik) was used to obtain a preliminary diagnostic impression and to assure the adequacy of the EM specimen for problematic cases. Our experience suggests that EM is being relied upon with greater frequency in the study of FNA specimens because it is an accurate and cost-effective diagnostic procedure. The use of a rapid interpretation (Diff-Quik stain) enhances the quality of the EM specimen and, as in surgical pathology, the EM examination increases the accuracy and specificity of the FNA biopsy diagnosis.

Biopsy, Needle↗
PubMedDate not supplied

Diagnostic accuracy and role of immediate interpretation of fine needle aspiration biopsy specimens from various sites.

A statistical analysis of the accuracy of the immediate interpretation of 425 fine needle aspiration (FNA) biopsies from various sites was performed. Preliminary interpretation of Diff-Quik-stained smears was rendered within a few minutes after performing the FNA biopsy, using diagnostic terminology similar to that of a surgical pathology report. The immediate assessment was documented in the formal cytology report and compared to the final diagnosis. For the entire series, the immediate interpretation had a sensitivity of 96%, a specificity of 97%, a positive predictive value (PV) of 98%, a negative PV of 95% and an efficiency of the test of 96%. There were 14 false-negative or falsely insufficient immediate interpretations and one false-positive immediate diagnosis. The diagnostic accuracy of the immediate interpretation of FNA biopsies from specific sites was also calculated; FNA biopsies of the pancreas were the least accurate procedure, having a sensitivity of 60% but a specificity of 100%. The role of the immediate interpretation of FNA biopsies is similar to the use of frozen sections in surgical pathology. An immediate assessment can (1) determine whether an adequate specimen is present, (2) render a specific preliminary diagnosis, (3) guide further clinical investigations or treatment, and (4) determine whether ancillary studies are needed to make a more accurate or specific diagnosis from the FNA specimen. Our results indicate that the immediate interpretation of FNA biopsies is an accurate procedure that should be routinely employed.

Biopsy, Needle↗
PubMedDate not supplied

Fine needle aspiration cytology of adenosis tumor of the breast. With immunocytochemical and ultrastructural observations.

The fine needle aspiration (FNA) findings of multinodular sclerosing adenosis forming a discrete lesion (so-called "adenosis tumor") of the breast are presented. The findings in this case and a review of the literature indicate that adenosis tumor is an unusual breast lesion that can clinically and histologically be confused with breast carcinoma, especially at the time of frozen section. FNA biopsy demonstrated uniform groups of ductal cells, stromal fragments and many stripped bipolar nuclei, which led to a correct diagnosis of a benign proliferative breast lesion, but not to a specific diagnosis of adenosis tumor. Immunoperoxidase staining for muscle actin demonstrated positive staining of many bipolar spindle-shaped cells, indicative of myoepithelial cells. Immunohistochemical studies on the resected specimen demonstrated actin positivity of myoepithelial cells and intact linear staining of type IV collagen around the ductules. Ultrastructural examination demonstrated ductal cells with surrounding myoepithelial cells resting on a delicate basal lamina, with surrounding bundles of collagen in the interstitial space. This appears to be the first FNA cytologic description of this unusual breast tumor and the first immunohistochemical and ultrastructural characterization of this lesion. FNA cytologic examination may more clearly identify the benign nature of the breast mass than frozen section.

Adult↗