Case report: malignant peritoneal mesothelioma in two siblings.

BACKGROUND: Mesothelioma is a rare tumor, linked with occupational asbestos exposure. This association has been used to explain clustering of cases within families. Newer evidence, however, supports a possible genetic predisposition for this tumor. CASE: Our patient's brother was diagnosed with advanced stage malignant peritoneal mesothelioma in August 1995 at age of 42, he underwent tumor-reductive surgery followed by chemotherapy. He underwent a repeat cytoreductive surgery in September 1996 and further chemotherapy. He died of disease in December 1996. Our patient underwent cytoreductive surgery in May 1999 at age of 49 for advanced stage malignant peritoneal mesothelioma with suboptimal debulking. She received multiple chemotherapy regimens, including most recently experimental targeted agents, for slow progressing disease. She is presently alive with clinical disease 6 years from diagnosis. CONCLUSION: This is the first report of two siblings of different gender with malignant peritoneal mesothelioma and only average environmental asbestos exposure. It is highly likely that the family described in this case report has some form of inherited susceptibility to malignancy cancer gene, HLA type, or tumor suppressor gene mutation.

Alpha-inhibin immunoreactivity in soft-tissue neoplasia.

Antibodies directed against alpha-inhibin have been previously reported as staining both sex cord-stromal neoplasms as well as adrenal cortical tumors. This relatively restricted immunoreactivity pattern is useful in the assessment of retroperitoneal masses, especially in a setting of limited tissue (e.g., needle biopsy). However, no study to date has evaluated alpha-inhibin immunoreactivity in soft-tissue neoplasms, which frequently enter the differential diagnosis of retroperitoneal masses. We investigate the incidence of alpha-inhibin staining in a variety of soft-tissue neoplasms by using formalin-fixed, paraffin-embedded tissue sections from 282 previously classified soft-tissue neoplasms with anti-alpha-inhibin (Serotec, 1:75). A modified avidin-biotin complex method was used after heat-induced epitope retrieval. Cytoplasmic granular staining was considered positive. Of the 282 tumors studied, a total of 8 (2.8%) demonstrated positive staining with anti-alpha-inhibin antibody. These included 4 of 25 liposarcomas (16%), 2 of 18 angiosarcomas (11%), 1 of 48 lipomas (2.1%), and 1 of 1 rhabdomyoma (100%). Negative staining was noted among hemangiomas (0/28), schwannomas (0/32), leiomyomas (0/16), fibrosarcomas (0/2), fibromas (0/11), dermatofibromas (0/9), neurofibromas (0/6), synovial sarcomas (0/15), rhabdomyosarcomas (0/10), Triton tumors (0/2), and malignant fibrous histiocytomas (0/59). We conclude that rare soft-tissue tumors, especially those exhibiting either lipomatous or vascular differentiation, demonstrate alpha-inhibin immunoreactivity. These findings re-emphasize the need for a well-construed antibody panel when immunohistochemical methods are employed in the evaluation of retroperitoneal neoplasms. However, the rarity of alpha-inhibin expression by soft-tissue neoplasms provides further support for its overall specificity as a marker of adrenal cortical differentiation in the biopsy evaluation of a retroperitoneal mass.

Pathologic findings in reduction mammaplasty specimens.

Reduction mammaplasty (RM) is a common surgical procedure that yields a variable amount of tissue for pathologic examination. Occult breast carcinomas are detected rarely in these specimens. We evaluated the pathologic findings in RM specimens performed in our institution during an 11.5-year period (July 1989 to December 2000). A total of 560 patients who had undergone RM were identified, 503 bilateral and 57 unilateral. The average number of blocks submitted per breast was 3.9 (range, 1-23). Pathologic changes were present in 338 cases (60.4%). Unsuspected carcinomas (small invasive carcinomas, 3; ductal carcinoma in situ, 1) were found in 4 cases (0.7%). Atypical ductal and/or atypical lobular hyperplasia were identified in 8 cases (1.4%). Lesions associated with a mildly increased carcinoma risk (moderate/florid ductal hyperplasia, sclerosing adenosis, and papilloma) were identified in 52 cases (9.3%). Other findings included fibrocystic changes, fibrosis, mild ductal hyperplasia, fibroadenoma, and adenosis. Pathologic examination of RM specimens provides important clinical information and should be performed routinely.

To step or not to step: an approach to clinically diagnosed polyps with no initial pathologic finding.

We determined whether there were additional diagnostic findings in additional level sections performed on polyps with no pathologic diagnosis (NPD) or those in which only lymphoid aggregates (LAs) were seen initially and determined the level at which findings were identified. All colorectal biopsy specimens submitted with a clinical diagnosis of polyp during a 6-month period were included (N = 733). Initially, 3 level sections were cut for each polyp, and if a cause for the polyp was found, no additional levels were evaluated. If LAs or no cause for the polyp was found, 5 additional levels through each block were examined. Any diagnostic findings and the level at which they were identified were recorded. A discrete cause for the polyp was identified in routine levels in 574 cases (78.3%). Deeper levels were performed in 159: 23 for clarification of a suspected diagnosis, 38 for LAs, and 98 for NPD. Findings were identified in 31 (22.8%) of 136 stepped for LA or NPD with neoplastic findings in 13 (9.6%). Most diagnoses were identified in levels 4 or 5, but tubular adenomas were found in levels 7 and 8. These results support level sectioning specimens submitted as polyps with NPD or LAs on initial sections.