G. Reza Hafez

Merkel cells and merkel cell tumors ultrastructure, immunocytochemistry and review of the literature

Certain monomorphic cellular tumors that occur in the dermis have been called trabecular carcinomas or Merkel cell tumors. Forty‐six cases have been reported to date and the literature on these is reviewed here, with six additional cases reported. Cytologic features include sparse cytoplasm, dispersed chromatin with inconspicuous nucleoli in round nuclei and many mitoses. Trabeeulae and pseudorosettes may be identified. Electron microscopy is required for definitive diagnosis. Like normal Merkel cells, tumor cells contain electron‐dense granules (80–200 nm), 10 mm filaments and desmosomes. Filament‐rich cytoplasmic spikes were found in four tumors. These resemble corresponding protrusions of normal Merkel cells and have not been described in other APUDomas. Cancer 52:238‐245, 1983.

Malignant schwannoma: a light microscopic and ultrastructural study.

The light microscopic and ultrastructural features of 3 cases of malignant schwannoma were studied and compared with those of other types of soft‐tissue sarcoma. The tumor in 1 of these cases originated in an intercostal nerve and was composed of compactly arranged spindle‐shaped tumor cells. The other 2 cases showed osteogenic areas in addition to exhibiting prominent nuclear palisading, focal myxoid changes, and a rosette‐like arrangement of tumor cells. The tumor in 1 of these latter cases occurred at the site of a preexisting neurofibroma. The Schwann cell origin of these tumors is strongly supported by the ultrastructural findings of basement membranes and conspicuous intercellular junctions in all 3 cases and dense‐core granules in 1.

Angiosarcoma of the Liver and Spleen in an Infant

A 14-month-old white male was diagnosed as having angiosarcoma of both the liver and spleen. At 17 months he developed pulmonary metastases and died. There was no apparent environmental or hormonal exposure either prenatally or during infancy. The malignant tumor probably arose from its benign counterpart (hemangioendothelioma), which was found in the spleen. This is the fifth case reported of splenic angiosarcoma in the pediatric age group (18 years or younger).

Immunocytochemistry of acinic cell carcinomas and mixed tumors of salivary glands

Antisera of several secretory products of the salivary gland were used to investigate the histogenesis of acinic cell tumors and mixed salivary gland tumors for comparison. Amylase, lactoferrin, secretory piece, and proline‐rich protein (PRP) immunoreactivity was detected in the majority of acinic cell tumors; staining was focal, except for PRP, which was diffuse. Lysozyme immunoreactivity was rare. There was discordance for immunoreactivity with several antisera in identifiable tumor lobules of half of the neoplasms. An antikeratin serum outlined microcystic and follicular areas but rarely solid foci. These findings support the contention that acinic cell tumors derive from a tubular type stem cell. Lactoferrin and secretory piece immunoreactivity was not common in mixed tumors and was confined to scattered ductal cells and luminal contents. Rare small foci of amylase and PRP immunoreactivity were found in two mixed tumors only.

Neurotropic melanoma of the vulva

A spindle cell melanoma of the clitoris was associated with a large area of lentiginous melanocytic dysplasia in the vulva of a 51‐year‐old woman. There was extensive neoplastic infiltration of the dermis, a desmoplastic reaction, and replacement of perineurial and Schwann cells by tumor cells (neurotropism). The superficial dysplastic components were pigmented, but melanosomes were not identified in a lymph node metastasis. Here the internuclear areas strongly resembled neuropil. Vulvar melanoma is rare, and this is the first report of neurotropic melanoma in this site.

Glucagonomas: Ultrastructure and immunocytochemistry

Pancreatic tumors harboring glucagon immunoreactive cells were found in four patients with diabetes mellitus. Alpha‐cell (glucagon) granules were present in three tumors; pancreatic polypeptide (PP) immunoreactive cells were detected in two. In two patients the tumors were malignant and one of these had the glucagonoma syndrome; the other was a member of a family with MEN‐type I syndrome. These cases illustrate three clinical subtypes of glucagonoma.

Combined serous microcystic adenoma and well-differentiated endocrine pancreatic neoplasm: a case report and review of the literature.

We report a case of combined microcystic adenoma and pancreatic endocrine neoplasm of the pancreas in a 53-year-old male patient. The pancreatic tumor was an incidental computed tomography scan finding and was not accompanied by gastrointestinal symptoms. The tumor was located in the head of the pancreas and was composed of numerous small cysts lined by uniform clear cells with a centrally located solid endocrine component. Four cases of similar neoplasm have recently been reported, exclusively in women. Literature review and case analysis indicate that combined microcystic adenoma and pancreatic endocrine neoplasm is characterized by the presence of pancreatic endocrine neoplasm within microcystic adenoma in the head of the pancreas, affects women more often than men, and presents at a younger age when compared to microcystic adenoma.

The consequences of unsuspected secondary ovarian neoplasia: A clinical presentation of four case histories

Secondary ovarian neoplasia is a common clinical entity which represents 3 to 8% of all ovarian tumors. However, despite its apparent prevalence, it remains a diagnostic and management dilemma. The ability to differentiate primary ovarian carcinoma from metastatic disease to the ovary has significant therapeutic and prognostic implications. Four case histories are presented which will demonstrate the necessity of formulating a complete differential diagnosis as well as the need for a thorough preoperative bowel examination.

Coexistence of a Gonadoblastoma and Mixed Germ Cell-Sex Cord Stroma Tumor

A 46 XY woman with a dysgerminoma and gonadoblastoma is described. Both dysgerminoma-gonadoblastoma and mixed germ cell-sex cord stromal tissue was present upon microscopic examination. This case exemplifies the transition that can exist between these two distinctly separate tumors.

Case report 849

A 12-year-old boy had a 7-month history of progressive left wrist pain. The pain had slowly worsened in intensity until he had significant pain even on simple gripping with his left hand. On physical examination, no mass was palpable but there was pain with palpation over the capitale. The remainder of the physical examination and routine laboratory tests were normal. Radiographs of the wrist showed a mixed lytic and sclerotic lesion of the left capitale (Fig. 1A). Hypocycloidal tomograms revealed volar cortical disruption and central destruction with a thick rim of dense, marginal sclerosis (Fig. 1B). The lesion was subsequently biopsed and curetted. At the time of the operation, violation of the cortex on the volar aspect of the capitate was confirmed. The tumor tissue was gray and friable. Histological examination revealed uniformly distributed polygonal cells with abundant cytoplasm and large nuclei consistent with a diagnosis of chondroblastoma (Fig. 2). Cellular morphology was normal without mitotic figures.