Twenty cases of papillary cystic tumor of the pancreas were studied (19 female patients, one male patient; median age, 19.5 years). Most tumors developed in the head or body of the pancreas as well-circumscribed, large masses. Gross examination showed that they were solid, cystic, and hemorrhagic. Preoperative fine-needle aspiration biopsy anticipated the diagnosis in four cases. Histologic examination showed that uniform cells formed solid sheets, and loss of cohesion produced pseudopapillae. Hemorrhage, foam cells, cholesterol granulomas, and entrapped nests of pancreatic parenchyma were often found. Fifteen cases studied immunohistochemically were reactive for vimentin and alpha-1-antitrypsin, 13 expressed neuron-specific enolase, 2 expressed cytokeratin, and 1 expressed S-100 protein. None were reactive for pancreatic hormones, opioid peptides, hormonal receptors, or neuroendocrine markers. Electron microscopic examination in five cases showed oval nuclei, moderate amounts of rough endoplasmic reticulum, and many mitochondria; it also showed that annulate lamellae were common. No diagnostic secretory granules were found. DNA study in nine cases revealed a diploid GO/1 peak in eight and hyperdiploid (diploid index = 1.1) DNA content in one case. Fourteen patients with follow-up were free of disease (mean, 2.6 years). Papillary cystic tumor of the pancreas possibly originates from primordial pancreatic cells and lacks definite evidence of endocrine or exocrine differentiation.

Sex cord-stromal tumors of the pediatric testis present diagnostic and therapeutic challenges. This study examines the clinicopathologic features of 16 testicular sex cord-stromal tumors from children less than 18 years of age. Four juvenile granulosa cell tumors and five tumors of Sertoli or incomplete differentiation in this study had high mitotic rates and/or sarcomatoid areas that suggested malignancy, but none of these children developed recurrence or metastases. Some of these tumors had been initially misdiagnosed as yolk sac tumors or rhabdomyosarcomas because of the presence of areas superficially resembling these neoplasms. These morphologic pitfalls have received little attention in the literature. Even incompletely differentiated sex cord-stromal tumors have at least focal areas characteristic of juvenile granulosa or Sertoli cell differentiation. In addition, immunohistochemical negativity for alpha-fetoprotein, muscle specific actin, and desmin are useful for ruling out yolk sac tumor and rhabdomyosarcoma. Four patients had Leydig cell tumors and three had large cell calcifying Sertoli cell tumors. Children with Leydig cell tumors are not at risk for metastasis, but children with large cell calcifying Sertoli cell tumors are at risk for endocrine syndromes as illustrated by one of our cases. The differential diagnosis of these tumors is also discussed.

No abstract

Two cases of fibromatosis of the breast, characterized by a proliferation of spindle cells containing intracytoplasmic, spherical, eosinophilic inclusion bodies, are reported. The light and electron microscopic features, as well as the immunohistochemical features, are indistinguishable from those found in infantile digital fibromatosis. The proliferating spindle cells are characterized as myofibroblasts, whereas the inclusion bodies show an immunohistochemically nonreactive, hollow-like pattern with peripheral reactivity for actin filaments. This lesion, observed for the first time in the breast, expands the number of extradigital inclusion body fibromatoses.

No abstract