Meningioma presenting as an intraoral mass in a patient with neurofibromatosis type 1.

A 77-year-old woman with neurofibromatosis type 1 presented with ill-fitting dentures due to intraoral extension of a right temporal fossa mass. Computed tomographic scanning demonstrated that the masticator space mass bowed the zygomatic arch and remodeled the lateral orbit and maxillary sinus walls, findings that were consistent with the clinical diagnosis of a neurofibroma with possible malignant transformation. However, light microscopic, immunohistochemical, and ultrastructural examination of tissue from an incisional biopsy specimen were diagnostic of meningioma. This case illustrates that the clinicopathologic differential diagnosis of an enlarging mass in patient with neurofibromatosis should include sporadic, unrelated neoplasms as well as tumors known to be associated with the syndrome.

Intracystic papillary carcinoma of the male breast. Immunohistochemical and ultrastructural study.

We report a case of mammary intracystic papillary carcinoma occurring in a 75-year-old man. The tumor was present on the left pectoral area for five years. Grossly, the neoplasm was a cystic structure 10 cm in diameter, with multiple intramural filiform papillae and small foci of cyst wall invasion. By transmission electron microscopy the tumor cells had the normal complement of organelles and also multiple electron-dense, membrane-bound secretory granules. These granules were also demonstrated with multiple stains for argyrophilia and with periodic acid-Schiff. Immunoperoxidase stains were negative for neuron-specific enolase, S100 protein, vasoactive intestinal peptide, corticotropin, calcitonin, lactalbumin, and bombesin, and positive for human heart factor (myoepithelial cells) and carcinoembryonic antigen. We believe that this rare neoplasm represents a variant of mammary adenocarcinoma and not a neuroendocrine (carcinoid) neoplasm.

Elastofibroma. A pseudotumor of myofibroblasts.

The fine structure of the cell of origin in elastofibroma showed features of both fibroblasts and smooth muscle cells with fibrils that formed parallel stacks 100 A in diameter and 100 A apart and occupied large areas of the cytoplasm of some cells and an abundance of rough endoplasmic reticulum. The myofibroblast has been reported in a variety of lesions and is also present in granulation tissue and hypertrophic scars. It is postulated, in accordance with previous reports, that myofibroblasts are instrumental in the repair process and that elastofibromas are a product of constant subclinical trauma and repair.

Ultrastructural observations in pleomorphic liposarcoma.

An ultrastructural study of pleomorphic liposarcoma with an unusual clinical presentation is described. A 69-year-old Caucasian female presented with recurrent superficial phlebitis of left leg, which responded only partially to conventional therapy. Following investigations, a mass was excised. Diagnosis of pleomorphic liposarcoma was made on microscopic examination. Numerous lipid droplets in the cytoplasm and often within intranuclear extensions of cytoplasm were seen on oil red O stain of frozen sections. Ultrastructural features are quite distinctive. The cells varied from small to often large pleomorphic cells with numerous lipid spaces without limiting membrane, large pleomorphic nuclei, and an abundance of cytoplasmic organelles. Centrioles were very prominent, in close proximity to nuclei, and collections of autophagocytic inclusions. Intercellular collagen was immature and scant. These features are compared to ultrastructural features of malignant fibrous histiocytoma, pleomorphic rhabdomyosarcoma, and cardiac myxoma, indicating that ultrastructural features are distinctive and help differentiate similar soft tissue tumors.

Primary Kaposi's sarcoma of lymph nods.

An example of Kaposi's sarcoma with primary involvement of lymph nodes is reported. The patient, a woman, was admitted because of generalized lymphadenopathy and anemia. She was also known to have congestive heart failure of rheumatic origin. SMA-12 screening disclosed hypercalcemia on several occasions during her hospitalization. Levels of circulating parathormone and prostaglandins E2 and F were markedly increased. Total bone scan was negative for involvement by tumor. Electronmicroscopic examination of an involved lymph node disclosed secretory bodies in the cytoplasm of malignant cells and other cells, with clear indication of endothelial origin. The rarity of Kaposi's sarcoma with primary lymph nodal involvement in the United States is discussed. So far as is known by the authors, no example of Kaposi's sarcoma has been associated with hypercalcemia due to ectopic endocrine production.

Widespread bone involvement in sinus histiocytosis.

Sinus histiocytosis with massive lymphadenopathy is a rare disorder of the reticuloendothelial system with predilection for black children.