No abstract

Differentiation of reactive and/or atypical mesothelial cells from malignant epithelial cells in serous effusions remains a frequent diagnostic problem. Since epithelial membrane antigen (EMA) positive malignant cells in serous effusions have been reported in almost all adenocarcinomas and most malignant mesotheliomas, immunoreactivity for EMA is felt to be less useful than other antibodies in the workup of problematic serous effusions. However, immunostaining of reactive and/or atypical benign mesothelial cells for EMA has not been well studied, with only a few series reporting either weak or negative staining for EMA. This study was undertaken to evaluate how often reactive and/or atypical appearing mesothelial cells stain positively for EMA. One hundred eighty serous effusions (115 pleural, 55 peritoneal, and 10 pericardial) from 123 females and 57 males ages 20 to 89 yr were evaluated in which an antibody panel including EMA was performed on cell blocks (141 cases), cytospins (36 cases), or both (3 cases). Of the 100 cytologically positive cases, EMA immunoreactivity was present in 97/100 (97%) cases. One EMA negative case suspicious for a metastatic renal cell carcinoma was lost to follow-up and not included in the analysis. The remaining three negative cases consisted of malignancies not expected to have EMA positive cells (small cell carcinoma, neuroblastoma, and synovial sarcoma). Therefore, EMA was positive in virtually 100% of the remaining malignant cases. In the 78 cytologically negative cases, EMA positivity was present in 3/78 (3.8%) cases. Clinical follow-up of up to 14 mo in these three cases revealed no evidence of malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Inflammatory myopathies are a group of acquired disorders with histologic features of inflammation and nonspecific myopathic changes in the muscle fibers. Up to 25% of patients with clinical features of polymyositis reportedly have no inflammatory changes in their muscle biopsy specimens, but the absence of inflammatory infiltrates does not exclude an inflammatory myopathy. However, whether the lack of inflammation is caused by sampling variation or by a total lack of demonstrable inflammation in a particular patient has been unclear in the literature. The authors diagnosed polymyositis in six patients who underwent percutaneous muscle biopsy using a Bergstrom needle. Through one skin incision, the needle was inserted into different areas within the muscle compartment, obtaining three or four concurrent specimens from each patient. In all cases of needle biopsy, adequate tissue was obtained for histochemical and electron microscopic examination. All patients tolerated the procedure well and resumed normal daily activities the morning after biopsy. Although we saw inflammatory changes in at least one biopsy specimen from each patient, one or more of the remaining specimens contained no evidence of inflammation. This illustrates that inflammatory infiltrates can be focal in polymyositis. Because a specific diagnosis of inflammatory myopathy cannot be made in the absence of demonstrable inflammation, the diagnostic yield of multiple percutaneous needle biopsy specimen is potentially higher than that of the traditional single biopsy specimen obtained with the open surgical method.

Metastatic basal cell carcinomas of the skin are rare. We present the cytologic features of a metastatic basal cell carcinoma to the lung diagnosed by fine-needle aspiration biopsy. Cytologic examination revealed syncytial groups of relatively small cells with hyperchromatic, oval to spindle-shaped nuclei having high nuclear to cytoplasmic ratios. Immunocytochemical studies performed on the cell block sections revealed the malignant cells to be positive for cytokeratin (AE1/3) and negative for neuroendocrine markers, [neuron specific enolase (NSE) and chromogranin (Phe-5)]. We reviewed the literature related to metastatic basal cell carcinoma of the skin and discuss risk factors and mechanisms of metastatic spread. In addition, a discussion of the other entities that can enter into the differential diagnosis is presented along with the role of ancillary studies. To the best of our knowledge, we believe this is the first case report of the fine-needle aspiration (FNA) cytology of a basal cell carcinoma metastatic to the lung.

While the liver is commonly involved in systemic amyloidosis, review of the literature indicates that clinically evident hepatic amyloidosis is not usually encountered. Three patients with clinically unsuspected primary amyloid light chain (AL) type of amyloid osis diagnosed by liver biopsy are described. All patients presented with signs, symp toms, and biochemical abnormalities consistent with intrinsic liver disease. The first patient had cholestatic hepatitis with jaundice, the second had hepatomegaly and weight loss, and the third had cholestatic liver disease. All three liver biopsies showed extensive sinusoidal deposition of amyloid material that stained positively with Congo red with and without prior potassium permanganate digestion, consistent with AL type amyloid. Ultrastructural examination of one of the cases showed straight, non- branching fibrils having the characteristic appearance of amyloid. Immunocytochemi cal staining in another case revealed the hyaline material to be positive for lambda light chains and negative for kappa light chains. These cases demonstrate that primary amyloidosis can present with liver abnormalities that dominate the clinical picture and that liver biopsy may be the initial diagnostic procedure of unsuspected primary amyloidosis. Int J Surg Pathol 1 (1): 57-64, 1993