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Biomedical subjects

M Huntrakoon

Publications and source records attributed to M Huntrakoon.

At least 37 records · Page 2Linked to original sources

Systemic rhabdomyosarcoma presenting as leukemia: case report with ultrastructural study and reviews.

A 20-year-old white male was initially suspected clinically and pathologically of having an acute lymphoblastic leukemic process because of fatigue, severe anemia, thrombocytopenia, a leuko-erythroblastic peripheral blood picture, and a diffusely infiltrated bone marrow. Subsequent review of the bone marrow material indicated cytologic features consistent with either an embryonal, undifferentiated small cell mesenchymal malignancy or reticulo-endothelial malignancy. Ultimately, the electron microscopic (EM) study of the tumor proved to be diagnostic of rhabdomyosarcoma. An extensive search for a primary site of rhabdomyosarcoma did not show any lesion, although the genitourinary region was clinically suspected. The clinical course was a rapidly downhill one with extensive bone and CNS involvement. The patient died 5 months later. An autopsy permit was not obtained. This case emphasizes the occasional tendency of rhabdomyosarcoma to masquerade as a hematopoietic malignancy at the time of presentation and the usefulness of EM study in confirming a diagnosis.

Adult↗

Neuroendocrine carcinoma of the parotid gland: a report of two cases with ultrastructural and immunohistochemical studies.

Two cases of primary small cell carcinoma of the parotid gland are reported. This rare neoplasm usually presents as a painful or painless mass in the gland. The finding of neurosecretory granules by electron microscopic study, combined with strong immunoreactivity for neuron-specific enolase and chromogranin, confirms the true neuroendocrine origin of the carcinoma. This tumor appears to have a better prognosis than small cell carcinoma of the lung, which it resembles histologically.

Aged↗

Disseminated rhabdomyosarcoma of the urinary bladder in an adult.

A rare case of alveolar rhabdomyosarcoma of the urinary bladder, manifested as a systemic disease in a 51-year-old woman, was diagnosed at necropsy. Diffuse lytic bone lesions and extensive bone marrow involvement with a leukoerythroblastic blood picture led to an initial clinical diagnosis of a hematologic malignancy.

Bone Marrow↗

Malignant nerve-sheath neoplasms in neurofibromatosis: distinction from benign tumors by using imaging techniques.

Malignant peripheral nerve-sheath neoplasms frequently complicate neurofibromatosis causing pain, enlarging masses, or neurologic deficits. However, similar findings sometimes also occur with benign nerve neoplasms. Our study was done retrospectively to determine if imaging techniques can differentiate malignant from benign nerve tumors in neurofibromatosis. Eight patients with symptomatic neoplasms (three benign, five malignant) were studied by CT in eight, MR in six, and 67Ga-citrate scintigraphy in seven. Uptake of 67Ga occurred in all five malignant lesions but not in two benign neoplasms studied. On CT or MR, all eight lesions, including three benign neoplasms, showed inhomogeneities. Of five lesions with irregular, infiltrative margins on CT or MR, four were malignant and one was benign. Of three lesions with smooth margins, one was malignant and two were benign. One malignant neoplasm caused irregular bone destruction. Accordingly, CT and MR could not generally distinguish malignant from benign lesions with certainty. However, both CT and MR provided structural delineation to help surgical planning for both types of lesion. 67Ga scintigraphy appears promising as a screening technique to identify lesions with malignant degeneration in patients with neurofibromatosis. Any area of abnormal radiogallium uptake suggests malignancy warranting further evaluation by CT or MR. Biopsy of any questionable lesion is essential.

Adolescent↗

Extraskeletal Ewing's sarcoma.

A well documented case of extraskeletal Ewing's sarcoma arising in a finger of a 16-year-old man was studied by light microscopy, immunohistochemistry and electron microscopy. The differential diagnoses of similar "round cell neoplasms" are discussed. Emphasis is placed on the distinction between extraskeletal Ewing's sarcoma and peripheral neuroepithelioma.

Adolescent↗

Isolated perfused lung histamine release, lipid peroxidation, and tissue superoxide dismutase from rats exposed to normobaric hyperoxia.

Female Sprague-Dawley inbred rats were exposed to either 1 atm of 100% O2 for 24 h, or 65% O2 for 5 days, with or without pretreatment with disulfiram, an inhibitor of lung CuZn-SOD. After O2 exposure, the rats were killed, the lungs removed, and isolated perfused lungs (IPLs) prepared. The IPLs were perfused with modified Krebs-Henseleit buffer, and perfusate histamine, malondialdehyde (MDA), and lung tissue CuZn-SOD activity examined. Disulfiram administration decreased the LT50 of O2-exposed rats from 65 to 36 h. Histamine and MDA in the perfusate from the IPL prepared from rats exposed to 100% O2 for 24 h were markedly increased. When rats were pretreated with disulfiram and exposed to 100% O2 for 24 h, histamine and MDA were increased an additional 77% and 45%, respectively. In separate experiments, 100% O2 exposure significantly decreased lung CuZn-SOD activity by 40% while IPL histamine and MDA were significantly increased. However, exposure of rats to 65% O2 for 5 days decreased lung CuZn-SOD by 69% but did not affect IPL histamine release or perfusate MDA. These studies suggest that IPL histamine release and/or MDA may be an early biochemical marker for pulmonary O2 toxicity, that lung CuZn-SOD activity may not be the only determinant in O2 toxicity, and other defense mechanisms may play a vital protective role during sublethal O2 exposures.

Animals↗

Superficial spreading malignant melanoma with neurosarcomatous metastasis.

A case of neurosarcomatous nodal metastasis of superficial spreading malignant melanoma, without primary site desmoplasia or sarcomatous changes, is reported. Of particular interest regarding the metastasis are: the ultrastructural demonstration of numerous cytoplasmic microtubules, absence of premelanosomes, intense immunohistochemical reaction with S-100 protein antibody, and the presence, at the light microscopic level, of extranodal fibrosis. The primary lesion shows a pre-existing benign nevus and features suggestive of lamellar fibroplasia. The origin and histogenesis of melanocytic desmoplasia, in the context of a neural crest progenitor cell, and of lamellar fibroplasia, are discussed.

Adult↗

Juxtacortical osteosarcoma: a radiologic and histologic spectrum.

Radiologic and pathologic findings were analyzed in four patients with parosteal osteosarcomas, three with periosteal osteosarcomas and one with a high-grade surface osteosarcoma. Plain film and histologic findings considered together are usually distinctive and permit differentiation of these tumors from each other and from other lesions with which they are frequently confused. Prognosis and management are determined by tumor extent and histologic grade. Computed tomography is more accurate than conventional tomography, angiography, and bone scintigraphy for preoperative determination of tumor extent and for assessing tumor relationships to the bone cortex and medullary cavity. Histologically, parosteal osteosarcomas are usually low-grade, while periosteal and high-grade surface osteosarcomas are generally high-grade tumors and have worse prognoses. High-grade surface osteosarcoma, which is indistinguishable in behavior and histology from classical medullary osteosarcoma, requires more aggressive surgical management than parosteal and periosteal osteosarcomas.

Adolescent↗

Benign glandular inclusions in the abdominal lymph nodes of a man.

The occurrence of benign glandular inclusions in the abdominal lymph nodes of a man is reported. The cells lining the glands were most likely derived from metaplastic mesothelial cells. Awareness of these benign glandular inclusions is essential, in that they simulate metastatic adenocarcinoma morphologically.

Abdomen↗

Microcystic adenoma of the pancreas with myoepithelial cells. A hitherto undescribed morphologic feature.

A case of microcystic adenoma (glycogen-rich cystadenoma) of the exocrine pancreas in a 62-year-old white female presenting with adult-onset diabetes mellitus is reported. Clinical, histopathologic, and ultrastructural findings are discussed with particular emphasis on the presence of myoepithelial cells, a morphologic feature not seen in this tumor previously. The controversy over diabetes mellitus as a significant related factor is also discussed.

Adenoma↗

Thymic carcinoid tumor with Cushing's syndrome. Report of a case with electron microscopic and immunoperoxidase studies for neuron-specific enolase and corticotropin.

A partially encapsulated, 11-cm-diameter anterior mediastinal mass was resected from a 26-year-old man who appeared with signs and symptoms of Cushing's syndrome. Electron microscopic study disclosed cytoplasmic neurosecretory granules and positive immunoperoxidase reactions for neuron-specific enolase and corticotropin in the tumor cells. A lymph node metastasis was detected 11/2 years after the operation. It appears that a thymic carcinoid tumor is a specific entity.

14-3-3 Proteins↗

Oncocytic carcinoma of the pancreas.

A large firm 12.5 cm mass at the tail of pancreas was surgically resected in a 73-year-old white man. The tumor was composed of solid sheets of cells with abundant finely granular eosinophilic cytoplasm. Electron microscopic study revealed tumor cells which were packed with mitochondria, a feature characteristic of the oncocyte. Perineural invasion and direct extension into the parenchyma of the spleen was present, as well as metastasis to a lymph node. There appears not to be a report of a similar case.

Aged↗