Pituitary abscess after autologous bone marrow transplantation.

The first case of pituitary abscess arising in a patient during recovery from autologous bone marrow transplantation is reported. A 31-year-old man with a 9 month history of T-cell lymphoma died suddenly more than 60 days after successful treatment with high-dose cyclophosphamide, total body irradiation, and autologous bone marrow infusion. Autopsy revealed a pituitary abscess associated with clinically silent sphenoid sinusitis. Unique aspects of this case are presented and clinical and pathologic features of pituitary abscess are reviewed. Although rare, pituitary abscess may complicate recovery from bone marrow transplantation.

Virilization due to a Leydig cell adrenal adenoma.

Virilizing adrenal adenomas are rare, and Leydig cell adenomas of the adrenal rarer still. Our patient, a 60-year-old virilized woman, was found to have a Leydig cell adenoma. Virilization associated with normal 17-ketosteroid and elevated testosterone levels necessitates excluding an adrenal cause. Although one might expect high testosterone levels to suppress gonadotropins, this is not the case. In addition to other studies recommended for assessing the incidentally discovered adrenal mass, we would add a testosterone assay.

Bone marrow necrosis: an entity often overlooked.

Bone marrow necrosis is a poorly understood and frequently an unrecognized finding in routine bone marrow biopsies. Previous reports indicate the incidence of bone marrow necrosis ranges from 0.5 percent (rare) to approximately one-third of all bone marrow biopsies examined. Our studies indicate that the presence of bone marrow necrosis depends on the clinical condition of the patient. Overall, our incidence of bone marrow necrosis was 37 percent of the bone marrow biopsies examined. Of these, 26.4 percent was mild. 7.5 percent moderate, and 3.1 percent severe necrosis. The mechanism in most cases had an identifiable underlying etiology such as a malignancy, or vascular or cytotoxic damage, with a small percentage being unexplained. Bone marrow necrosis is seen across a wide range of conditions, including sickle cell diseases, AIDS, leukemia, lymphoma, metastatic carcinoma, anemia, sepsis, and other systemic diseases. Patients at the extremes of age, less than 20 years and greater than 70 years, usually demonstrate only small foci of necrosis (Grade I). Moderate (Grade II) and severe (Grade III) bone marrow necrosis are often associated with life threatening illnesses, with most of these being hematologic malignancies or bone marrow metastases. The prognosis associated with bone marrow necrosis seems to be dependent on the underlying primary clinical condition regardless of the degree of necrosis observed.

Thyroid carcinosarcoma.

A thyroid carcinosarcoma composed of follicular carcinoma intermixed with osteosarcoma and chondrosarcoma was studied. Results of immunoperoxidase staining for thyroglobulin were positive in the areas of follicular carcinoma and negative in the sarcomatous component. Likewise, the carcinomatous areas showed thyroid epithelial characteristics by ultrastructure, while the sarcomatous areas showed typical mesenchymal differentiation. This is an extremely rare neoplasm, with only 16 cases reported in the literature. It occurs predominantly in elderly women, is thought to arise through a process of neoplastic metaplasia, and has a uniformly dismal prognosis. Immunoperoxidase and ultrastructural studies, the first reported in such lesions, proved helpful in ascertaining the sarcomatous nature of the anaplastic, mesenchymal component of this unusual and aggressive neoplasm.

Virilizing Leydig cell adenoma of adrenal gland.

We describe the third report testosterone-producing, virilizing, adrenal Leydig cell adenoma, which was identified in a oophorectomized postmenopausal female patient. Light- and electron-microscopy demonstrated typical Leydig cell differentiation, including numerous intracytoplasmic and intranuclear Reinke crystals and rice-like bodies (elementary tubular inclusions). Testosterone production by the adenoma was demonstrated by the immunoperoxidase technique. We propose that adrenal Leydig cell adenomas arise as a result of ovarian gonadal stromal metaplasia associated with elevated follicle-stimulating hormone and luteinizing hormone in the postmenopausal female patient. Adrenal Leydig cell lesions must be considered in the virilized woman with elevated testosterone levels and normal levels of the adrenal androgens and their 17-ketosteroid metabolites.

Osteoclastic giant cell tumor of the pancreas. Aspiration cytology, light microscopy, and ultrastructure with review of the literature.

The osteoclastic giant cell tumor of the pancreas is a rare primary neoplasm that by light and electron microscopy mimics giant cell tumor of bone. In the proper clinical setting, this lesion can be diagnosed by fine needle aspiration. Review of 10 cases reveals a female predominance, a median survival of 12 months, and a tendency for local invasion, rather than lymphatic or distant metastasis, and for invasion of large veins. An epithelial origin is favored for this malignant neoplasm, which expresses varying degrees of mesenchymal differentiation.

Oncocytic mucoepidermoid tumor of the bronchus.

Mucoepidermoid neoplasms of the bronchus are uncommon tumors believed to arise from bronchial mucus glands. Reported ultrastructural evaluation has been limited to two cases in a single publication. The authors report the light microscopic and ultrastructural features of a third case with similar findings. An unusual finding not previously reported was the presence of numerous typical onocytes shown by light and electron microscopy. Morphologic forms intermediate between the mucus cells, epidermoid cells, and oncocytes were identified ultrastructurally. The origin of onocytes has been of some controversy. The presence of these cells associated with a mucoepidermoid tumor of the bronchus suggests a common progenitor cell. The transitional forms identified ultrastructurally support the notion that oncocytes are the result of a metaplastic process.

Branching pattern in CT scans of mucin producing carcinoma metastases to the liver.

Intrahepatic calcification occurring in a branching pattern with a periportal distribution has not previously been described in hepatic metastases. We report a patient with a unique branching pattern of calcified hepatic metastases. There were no low density masses associated with the calcifications as is usually seen in calcified metastases to the liver demonstrated by computed tomography.

B-cell and T-cell lymphomas and other associated diseases induced by an infectious DNA viroid-like agent in hamsters (Mesocricetus auratus).

Five epidemics of diffuse, poorly differentiated lymphocytic, immunoblastic, and plasmacytoid lymphoma induced by an infectious, horizontally transmitting viroidlike agent have occurred in two hamster facilities. Incidence summaries and pathologic characteristics of the lymphomas induced in LSH and LVG hamsters are presented. An elevated leukocyte count with a marked increase in neutrophils and a significant decrease in small mononuclear lymphocytes was detected in 5-week-old but not in 10- or 25-week-old LVG hamsters born in the facility contaminated with the lymphoma-inducing agent. Three-week-old LVG hamsters exposed to the contaminated facility showed no similar hematologic change at 5 weeks of age or 5 weeks of exposure. Several associated syndromes, including an intussusception disease, pyelonephritis, inflammatory bowel disease, and body warts associated with the presence of the causative viroidlike agent in the contaminated colonies are described. Details of the epidemiology of the disease, karyology, viral studies, and correlation with several epidemics in other laboratories are presented.