Gastrointestinal involvement in paroxysmal nocturnal hemoglobinuria: first report of electron microscopic findings.

Thrombotic complications, particularly microthrombi involving intraabdominal veins leading to intestinal ischemia, have remained a major cause of morbidity in patients with paroxysmal nocturnal hemoglobinuria (PNH). While intestinal ischemia has been postulated to be the cause of recurrent bouts of abdominal pain in this population, direct antemortem evidence for this complication is scarcely documented in the literature. We describe a case of PNH in a patient who presented with abdominal distress three years after the initial diagnosis was established. Clinical features and a combination of diagnostic modalities, including radiography, endoscopy, and histology were used to make the prompt diagnosis of intestinal ischemia. This is the first case in which the electronic microscopy of the gastrointestinal lesion is described. Our patient was successfully treated with conservative measures and anticoagulation.

Endometrial stromal sarcoma with focal smooth muscle differentiation: recurrence after 17 years: a follow-up report with discussion of the nomenclature.

In 1977, a case report was published describing a 28-year-old women with an endometrial stromal tumor that showed foci of myogenic differentiation. The term "stromomyoma" was introduced to encompass both this type of neoplasm as well as "uterine neoplasms resembling ovarian sex-cord tumors" (UTROSCTs). More than 17 years later, the tumor recurred, involving the right ovary, sigmoid colon, small bowel, abdominal wall and omentum. The histologic and electron microscopic similarities between the recurrent tumor and the primary neoplasm were confirmed. Applying the recent classification and diagnostic criteria of endometrial mesenchymal neoplasms, we have concluded that this tumor was a low-grade endometrial stromal sarcoma (LGSS). The formerly proposed term "stromomyoma" implies a benign tumor, in contrast to the obviously malignant nature of this particular tumor. Focal myogenic differentiation of LGSS is not an uncommon finding and does not warrant a separate diagnostic or prognostic entity. UTROSCTs and endometrial stromal sarcomas are two separate diagnostic entities, and combining them under an inclusive terminology is not appropriate.

Prolactin-producing pituitary carcinoma with pulmonary metastases.

Pituitary adenomas rarely are metastatic. Extracranial visceral metastases of prolactinomas were not previously reported. The authors report a case of a 34-year-old man with a prolactin-producing pituitary carcinoma and histologically proven lung metastases. Pathologic examination of the pulmonary spread included electron microscopy and immunohistochemistry; these confirmed prolactin production by the tumor. The patient's presentation at initial diagnosis, disease recurrence, clinical course, management, and response to therapy (with its theoretic basis) are detailed. Despite the use of dopamine analogues (to tolerance and in combination), there was documented intracranial and extracranial disease progression. Possible future therapeutic maneuvers are discussed.

Primary leiomyosarcoma of adrenal gland. Case report with immunohistochemical and ultrastructural study.

A primary leiomyosarcoma of the right adrenal gland is reported in a 49-year-old male who presented with progressive flank pain. This is the second case in the English language literature and the first to have documentation of malignant behavior. The tumor measured 11 cm in diameter and showed marked necrosis with prominent mitotic activity (average 15 per 10 high-power fields). Smooth muscle differentiation was apparent ultrastructurally and confirmed by positive immunostaining for muscle-specific and alpha-smooth muscle actin. Bony metastases developed; following palliative treatment with radiation and chemotherapy, the patient is alive with tumor 9 months later. Origin from smooth muscle associated with the central adrenal vein or its tributaries is proposed.

Gingival granular cell tumors of the newborn. An ultrastructural and immunohistochemical study.

Gingival granular cell tumor of the newborn, or congenital epulis, is a rare congenital lesion of uncertain histogenesis located exclusively on the alveolar ridge with marked predilection for female infants. Although histologically similar to the more ubiquitous granular cell tumor or myoblastoma, ultrastructural and immunohistochemical studies support separate histogenetic pathways for the two lesions. A newborn female infant with three gingival granular cell tumors is described herein along with immunohistochemical and ultrastructural observations. There was positive immunostaining for vimentin but staining for S100 protein was uniformly negative. Immunocytochemical assay for estrogen and progesterone receptors was also negative. The findings indicate a mesenchymal origin and the demonstration of intermediate filaments with fusiform electron densities suggests that some of the granular cells have morphologic attributes of myofibroblasts.

Histopathologic analysis of suspected amiodarone hepatotoxicity.

This analysis of the morphology of suspected amiodarone (AD) liver disease is based on a study of liver specimens from 17 individuals. Changes similar to alcoholic liver injury were commonly seen. Steatosis, both macrovesicular and microvesicular, was the most frequent histopathologic feature. Ballooning of hepatocytes, Mallory bodies, and fibrosis were also common. Other changes included nuclear unrest, acidophilic bodies, foam cells, glycogenated nuclei, and portal inflammation. Characteristic lamellar lysosomal inclusion bodies representing phospholipidosis were found in two of 14 specimens studied ultrastructurally. These changes of pseudoalcoholic hepatitis and/or phospholipidosis were present in liver specimens from asymptomatic, anicteric patients with mild elevations in serum aminotransferase or alkaline phosphatase values with or without hepatomegaly, as well as in patients with clinically overt symptoms of hepatotoxicity. Phospholipidosis appears to be a generalized systemic effect of cationic amphophilic compounds, such as AD. The cytotoxic pseudoalcoholic changes appear to be an independent phenomenon in susceptible patients, whom we speculate may have been unable or less able to metabolize AD through normal pathways. The true incidence of hepatic injury from AD remains to be determined from prospective evaluations of pretreatment and follow-up liver biopsies.

Establishment and characterization of an epithelial cell line from the rat submandibular gland.

An epithelial cell line, RSMTx, has been established from the submandibular gland of weanling Fisher 344 rats by treatment of explanted tissue clumps with 3-methylcholanthrene. These cells exhibit a polygonal shape on light microscopy and a polar appearance, with desmosomes, terminal bar-like structures, surface microvilli and cytoplasmic interdigitations, when examined by electron microscopy. The cells react positively with an antiserum to cytoskeletal keratin, and a commercial monoclonal antibody to an "epithelial membrane antigen." An antiserum, prepared against early passage cells in hamsters, reacts primarily with ductal elements in tissue sections of submandibular gland, as does an antiserum prepared in mice with late passage cells. The cells are easily passaged and have been maintained for more than two years in continuous culture.

Langerhans cells in dermoid cysts: transmission electron microscopic, cytochemical and immunofluorescent observations.

Langerhans cells were detected in squamous, stratified epithelia lining human dermoid cysts. Their presence was assayed by ATPase staining and reactivity with heteroantisera against "Ia-like" antigens. Transmission electron microscopic studies demonstrated variations in the numbers of cells showing Birbeck granules in epithelia with different degrees of keratinization. Indeterminate cells (i.e. lacking granules), were more frequent in epithelia showing combined mucous and keratinizing differentiation. Membrane-coating-granules and keratohyalin granules were present in epithelia containing Langerhans cells with clearly identifiable Birbeck granules. Interepithelial mast cells were observed in epithelia with mucous differentiation. A relationship between Langerhans cells and keratinization was suggested. Such non-immune functions are compatible with the known macrophage characteristics of the cell.