The clinicopathologic characteristics and outcome of atypical anti-glomerular basement membrane nephritis

Classic anti-glomerular basement membrane (GBM) disease presents with rapidly progressive glomerulonephritis (GN) with or without pulmonary hemorrhage. On biopsy typical disease displays bright polytypic linear GBM staining for IgG by immunofluorescence and diffuse crescentic/necrotizing GN on light microscopy. Here, we studied 20 patients with atypical anti-GBM nephritis typified by bright linear GBM staining for immunoglobulins but without a diffuse crescentic phenotype. Patients had hematuria, proteinuria, and mild renal insufficiency, without pulmonary hemorrhage. Light microscopy showed endocapillary proliferative GN in 9 patients, mesangial proliferative GN in 6, membranoproliferative GN in 3, and focal segmental glomerulosclerosis with mesangial hypercellularity in 2. Eight of the 20 showed features of microangiopathy. Crescents/necrosis were absent in 12 and were focal in 8 patients. Bright linear GBM staining for IgG was seen in 17 patients, IgM in 2, and IgA in 1 patient, which was polytypic in 10 patients and monotypic in 10 patients. No circulating α3NC1 antibodies were detected by commercial ELISA. The 1-year patient and renal survival rates were 93% and 85%, respectively. Thus, atypical anti-GBM nephritis is a rare variant of anti-GBM disease characterized clinically by an indolent course, no pulmonary involvement, and undetectable circulating α3NC1 antibodies. Further studies are needed to characterize the molecular architecture of GBM autoantigens in these patients and establish optimal therapy.

Gemcitabine associated vasculitis leading to necrotizing enterocolitis and death in women undergoing primary treatment for epithelial ovarian/peritoneal cancer

We present two patients who developed necrotizing enterocolitis following their first cycle of chemotherapy for epithelial ovarian/peritoneal cancer. After optimal cytoreductive surgery, both women received gemcitabine as part of a chemotherapy protocol. One patient developed necrotizing enterocolitis, 1 day after chemotherapy and the other 8 days after chemotherapy. The first patient succumbed to the enterocolitis despite aggressive supportive care. The second patient succumbed despite both aggressive supportive care and surgical intervention. Pathologic review for both patients revealed a drug induced vasculitis causing necrotizing enterocolitis.

-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.