Pigmented solid-pseudopapillary neoplasm of the pancreas.

A hitherto unrecognized variant of solid-pseudopapillary neoplasm of the pancreas is reported. The tumor presented in the pancreatic head of a 57-year-old female patient. It was a well-circumscribed, encapsulated nodule measuring 27 mm in diameter, with variegated yellow to brown and gray cut surface. Histologically, the neoplasm was composed of uniform polyhedral cells arranged around delicate fibrovascular cores retaining their solid pattern in the periphery, whereas central parts of the tumor were characterized by the formation of papillae and smaller pseudocysts. Neither mitotic activity nor invasive growth were found. Immunohistochemically, tumor cells were positive for vimentin, neuron-specific enolase, and CD56, whereas they were negative in reactions with antibodies directed against other neuroendocrine markers, cytokeratins, melanocytic markers, and pancreatic amylase. In addition to these typical findings, intracellular pigmented granules were found in the darker brown zones of the tumor. They were positively stained in periodic acid-Schiff reaction after diastase digestion, sudan black B, and in Schmorl stain. In contrast, they were not stained with Fontana-Masson, Ziehl-Neelsen, and Perls stains. Ultrastructurally, the pigment consisted of dense granules with lipid droplets resembling modified lysosomes. These results exclude the possibility of a melanogenic nature of the pigment and instead determine it as lipofuscin.

Reactive syringofibroadenomatous hyperplasia in peristomal skin with formation of hybrid epidermal-colonic mucosa glandular structures, intraepidermal areas of sebaceous differentiation, induction of hair follicles, and features of human papillomavirus infection: a diagnostic pitfall.

We report a case of reactive syringofibroadenomatous hyperplasia in peristomal skin. The patient was a 62-year-old woman who had undergone abdominoperineal resection of the rectum for rectal adenocarcinoma with subsequent colostomy 2 years earlier. Clinically, a nodule and small, whitish, warty lesions developed at the outer margin of the stoma extending onto the adjacent skin. Following a clinical suspicion of adenocarcinoma, recurrent at the colostomy site, a 5 x 4 x 3-cm excision of the peristomal skin and the affected portion of the stoma was performed and submitted for histologic examination. The biopsy revealed a peculiar composite lesion of reactive syringofibroadenomatous hyperplasia and the excised part of the stoma. Several unusual histopathological features were detected in the syringofibroadenomatous part of the lesion such as the formation of plentiful hybrid epidermal-colonic mucosa glandular structures, intraepidermal areas of sebaceous differentiation, koilocytic changes, induction of rudimentary hair follicles, and intradermal mucinous lakes. The cellular composition of the glandular structures was mainly similar to that seen in a normal colonic mucosa epithelium. They also contained occasional Paneth cells. Being located at a distance from the stoma, these accentuated colonic mucosa epithelial glands reaching the epidermis may be a diagnostic pitfall prompting the consideration of adenocarcinoma involving the stoma. The rudimentary follicles and sebaceous differentiation were probably induced by an altered stroma and/or human papillomavirus (HPV): HPV, type 36 was identified by PCR using consensus primers followed by sequencing of the PCR products.

QF-PCR examination of parental and meiotic origin of trisomy 21 in Central and Eastern Europe.

Study of parental/meiotic origin of free trisomy 21 in nuclear families from Russia (70 cases), Ukraine (32 cases), and 22 from Germany revealed maternal nondisjunction in 77.3% (Germany), 93.8% (Ukraine), and 91.4% (Russia), paternal origin in 13.6%, 6.2%, and 8.6%, respectively. Maternal meiosis I errors were found in 84.4% (Ukraine), 77.1% (Russia), paternal origin in 3.1% (Ukraine), 2.9% (Russia). Maternal meiosis II errors occurred in 9.4% and 14.3% and paternal in 3.1% and 5.7% in Ukraine and Russia, respectively. No significant differences were found in maternal/paternal origin among Ukraine, Russia, Germany, and published data from other European regions.

Primary capillary hemangioblastoma of peripheral soft tissues.

A case of capillary hemangioblastoma located in the peripheral soft tissue of the inner ankle in a 74-year-old woman is presented. The tumor was an unencapsulated but sharply circumscribed nodule 2.5 cm in size, of a yellow-white color. It showed reddish-brown spots with small cysts up to 2 mm filled with blood. Grossly the tumor was not attached to any peripheral nerve. Signs of von Hippel-Lindau's disease were excluded by thorough clinical evaluation. No additional tumor or erythrocytosis was found in the patient clinically. Immunohistochemically, the tumor stromal cell reacted strongly with antibodies to S-100 protein, NSE, and calponin and they were negative with antibodies to GFAP, CD34, CD31, cytokeratins, actin, desmin, EMA, and HMB-45. Endothelium of the capillaries reacted positively with antibodies to CD31, CD34, and Factor VIII-related protein. Capillary pericytes were actin-positive. All cells of the tumor stained positively with antibody to vimentin. MIB1 antibody reacted only in very few cells (<1%). Ultrastructurally, the stromal cells contained electron-lucent cytoplasm with lipid droplets, a small amount of rough endoplasmic reticulum, and glycogen particles. No electron-dense structures typical of secretory granules were seen in the stromal cells. No mutation of coding sequence of VHL gene was found.