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At least 1,243 records · Page 69Linked to original sources
PubMed1977

Transplantable murine salivary gland carcinoma (myoepithelioma). I. Biologic behavior and ultrastructural features.

Three salivary gland adenocarcinomas that arose spontaneously in female BALB/c mice, originally being maintained for plasmacytoma (MOPC) investigations, were studied; only one of the original hosts was MOPC-bearing. The initial carcinomas clearly originated from the salivary gland, not the breast, and did not resemble plasma cell lesions. The submandibular gland was the site of origin in each instance. Lesions were identical to those described previously in strains A and C mice as myoepitheliomas, with intracellular fibrils positive by phosphotungstic acid-hematoxylin (PTAH) stain. Each cell line (A, B, and C) of the salivary gland carcinomas was serially transplanted for 28, 29 and 14 generations, respecitvely. The lesion was easily transplanted, achieved almost 100% takes, and uniformly killed the host in 6-12 weeks, with metastasis to the peritoneum and liver. A myeloproliferative reaction characterized by leukemoid changes regularly occurred during the growth of the tumors. Each transplant generation was identical to its original salivary gland precursor by light and electron microscopy. In their growth pattern, the tumors resembled sarcomas with large areas of spindle cells. Ultrastructurally, the neoplastic cells contained the organelles of acinar and possibly ductal cells and exhibited varying degrees of synthetic and secretory activity, characterized by abundant free ribosomes and granular ergastoplasm, with prominent canaliculi containing abundant secretory material. Numerous desmosomes were seen, as well as coarse filaments and fine fibrils in most tumors cells, particularly in cells exhibiting lesser degrees of secretion. The filaments most likely represented the PTAH-positive intracellular fibrils observed by light microscopy. All tumors had numerous cells with resting features.

Adenocarcinoma↗
PubMed1991

Oncocytic tumors of major salivary glands. A study of 68 cases with follow-up of 44 patients.

Oncocytic tumors rarely occur in major salivary glands and generally account for less than 1% of all salivary tumors. Until now, a large series of these tumors with long-term follow-up has been lacking. We report on 68 cases of oncocytic major salivary gland tumors with clinical data on 44 patients. Eighty-four percent occurred in the parotid (male to female ratio of 1:1), and 11% arose in the submandibular gland (six males, one female). Additionally, 5% were incidentally found in salivary nests of the upper cervical lymph nodes. The mean age of all patients was 58 years. Unexpectedly, 20% of the patients had either radiotherapy to the face or upper torso or long-term occupational radiation exposure, 5-40 years prior to tumor discovery. Patients with previous radiation exposure had a mean age of 43 years at tumor discovery as compared with 63 years for all other patients (p less than 0.01). Among 44 patients, there were four definite, documented cases of recurrences: two were multiple and bilateral. A minimum 7% incidence of bilateral disease was noted. An association exists among bilateral disease, tumor recurrence, and extensive clear cell change ("clear cell oncocytosis"). Only one case metastasized: an oncocytic adenocarcinoma of the submandibular gland. None of the oncocytomas studied (including three with perineural spread) metastasized after 0.5-38 years' follow-up (mean 12 years). The literature is reviewed with regard to cases of metastasizing malignant oncocytomas.

Adenolymphoma↗
PubMed1998

Pulmonary immunocytoma with massive crystal storing histiocytosis: a case report with review of literature.

An unusual immunocytoma (lymphoplasmacytoid lymphoma) composed predominantly of sheets of globoid and spindle-shaped crystal-storing histiocytes was detected incidentally in the right lung of a 72-year-old woman. Scattered lymphoplasmacytic aggregates within the tumor had monoclonality with anti-kappa immunoglobulin (Ig) M antibodies. The crystals were outlined positively by the same antibodies. They stained an intense blue with phosphotungstic acid-hematoxylin (PTAH) and were found during electron microscopy to be membrane bound and also within type I pneumocytes and the extracellular space. Excessive production of kappa IgM by neoplastic low-grade lymphoplasmacytoid cells of B-cell origin in an altered intra- or extracellular milieu may lead to crystallization and phagocytosis by reactive histiocytes. Review of the literature revealed seven more cases: four in the head and neck, and one each in the skin, the lymph node, and the lung. IgM was the most frequently crystallizing immunoglobulin (four of seven) and all had kappa light chains. The lesion needs to be differentiated from neoplastic and nonneoplastic histiocytic and lymphoplasmacytic disorders. The difference with bronchial mucosa-associated lymphoid tissue lymphoma and marginal zone lymphoma is, perhaps, semantic.

Aged↗
PubMed1999

Oncocytic mucoepidermoid carcinoma of the salivary glands.

Two parotid mucoepidermoid carcinomas with predominant oncocytic features were initially assessed on frozen section. Because of extensive oncocytic change, it was inferred that the lesions were most likely benign. Permanent sections revealed low-grade mucoepidermoid carcinoma with prominent oncocytic change (in more than 75% of the neoplasms) in both cases. Review of 48 additional consecutive cases of mucoepidermoid carcinoma of the salivary glands revealed prominent oncocytic change (accounting for 60% of the neoplasm) in one high-grade lesion. Phosphotungstic acid-hematoxylin stains revealed strong granular cytoplasmic staining in the oncocytic elements; immunohistochemical stains for antimitochondrial antibodies also showed intense immunoreactivity in these cells. Oncocytic change is not typically a prominent feature of mucoepidermoid carcinoma of the salivary glands, and to our knowledge, only three such cases have been reported previously. Because most salivary gland lesions with oncocytic change are benign, it is important to distinguish mucoepidermoid carcinoma from other entities that may show prominent oncocytic change. We report three additional examples of this rare lesion, two low-grade tumors and one high-grade tumor, and review our experience with oncocytic change in mucoepidermoid carcinoma of the salivary glands.

Adult↗
PubMed2001

Protein aggregation after focal brain ischemia and reperfusion.

Two hours of transient focal brain ischemia causes acute neuronal death in the striatal core region and a somewhat more delayed type of neuronal death in neocortex. The objective of the current study was to investigate protein aggregation and neuronal death after focal brain ischemia in rats. Brain ischemia was induced by 2 hours of middle cerebral artery occlusion. Protein aggregation was analyzed by electron microscopy, laser-scanning confocal microscopy, and Western blotting. Two hours of focal brain ischemia induced protein aggregation in ischemic neocortical neurons at 1 hour of reperfusion, and protein aggregation persisted until neuronal death at 24 hours of reperfusion. Protein aggregates were found in the neuronal soma, dendrites, and axons, and they were associated with intracellular membranous structures during the postischemic phase. High-resolution confocal microscopy showed that clumped protein aggregates surrounding nuclei and along dendrites were formed after brain ischemia. On Western blots, ubiquitinated proteins (ubi-proteins) were dramatically increased in neocortical tissues in the postischemic phase. The ubi-proteins were Triton-insoluble, indicating that they might be irreversibly aggregated. The formation of ubi-protein aggregates after ischemia correlated well with the observed decrease in free ubiquitin and neuronal death. The authors concluded that proteins are severely damaged and aggregated in neurons after focal ischemia. The authors propose that protein damage or aggregation may contribute to ischemic neuronal death.

Animals↗
PubMed1993

Papillary cystic tumor of the pancreas: a case indistinguishable from oncocytic carcinoma.

A case of papillary cystic tumor (PCT) of the pancreas in a 55-year-old woman is described. She presented with a gradually enlarging and painless abdominal mass for > 26 years. The tumor was encapsulated and measured 16 x 12 x 10 cm. The gross features and conventional light microscopic appearance of this tumor were consistent with the previously reported cases of PCT. Perineural and capsular invasions were found. In addition to the densely packed blue granules in the cytoplasm demonstrated by phosphotungstic acid-hematoxylin stain, ultrastructural study revealed the tumor cells to be packed with numerous mitochondria. These oncocytes comprised almost all the non-necrotic tumor areas. Therefore, this case was indistinguishable pathologically from oncocytic carcinoma of the pancreas. DNA flow cytometry showed a diploid pattern and low S phase fraction, indicating that the tumor has a low proliferative activity and a favorable prognosis.

Cell Cycle↗