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Biomedical subjects

B W Scheithauer

Publications and source records attributed to B W Scheithauer.

At least 379 records · Page 21Linked to original sources
PubMed1985

Intracranial germ cell tumors: pathobiological and immunohistochemical aspects of 70 cases.

Seventy cases of histologically verified intracranial germ cell tumor were reviewed: 43 germinomas, 16 immature teratomas, seven mature teratomas, two embryonal carcinomas, one choriocarcinoma, and one yolk sac tumor. The male-to-female ratio was 2.6:1. The average age was 19 years in patients with germinoma, 11 years in patients with immature teratoma, and 17 years in patients with mature teratoma. Duration of symptoms averaged 19 months for germinoma, three months for immature teratoma, and 11 months for mature teratoma. Sixty-six lesions were located in the midline. Fifty-eight percent of the germinomas arose anterior to the pineal gland, whereas 29% of the immature and 14% of the mature teratomas were located anteriorly. The histologic appearance of the germinomas was indistinguishable from that of the usual testicular seminoma. The immature teratomas contained tissue from all three germ layers and exhibited morphologic features of fetal tissue. Of 14 immature teratomas, seven contained, in addition, foci of other malignant germ cell elements; thus, there were two teratocarcinomas, two lesions with germinoma and immature teratoma, two lesions with extensive rhabdomyoblastic differentiation in an immature teratoma, and one lesion with both germinoma and embryonal carcinoma in addition to immature teratoma. The seven mature teratomas consisted of fully differentiated epithelial and mesenchymal tissues. In 23 cases, immunoperoxidase stains for human chorionic gonadotropin (HCG), alpha-fetoprotein (AFP), and carcino-embryonic antigen (CEA) revealed patterns which, with minor exceptions, were essentially identical to those found in genital germ cell lesions. Survival was longest for patients with germinomas. In classifying germ cell tumors of the central nervous system, the World Health Organization's (WHO) classification of testicular germ cell tumors is preferable to its present classification of intracranial germ cell tumors.

Adolescent↗
PubMed1984

Malignant peripheral nerve sheath tumors with divergent differentiation.

Malignant peripheral nerve sheath tumors are uncommon sarcomas of Schwann cell or fibroblastic derivation which occasionally show histologic evidence of focal divergent differentiation to rhabdomyosarcoma, osteosarcoma, chondrosarcoma, angiosarcoma, epithelial elements, or a combination thereof. The finding of these heterotopic elements in nerve sheath sarcomas is believed to illustrate the differentiating capacity of neuroectodermal tissue. The authors present the clinicopathologic features of 17 such tumors, which represent 14.7% of the malignant peripheral nerve sheath tumors in the authors' institutional experience. Most of the lesions were associated with von Recklinghausen's disease. These tumors do not seem to differ from ordinary malignant peripheral nerve sheath tumors in presentation, operative, gross, and microscopic features, response to therapy, or prognosis.

Adolescent↗
PubMed1984

Thymic carcinoid. A histologic, immunohistochemical, and ultrastructural study of 12 cases.

Twelve cases of thymic carcinoid were studied by electron microscopy and immunohistochemistry. Clinically, all of them presented either as asymptomatic, radiographically detected mediastinal masses or as neoplasms producing symptoms of thoracic structural displacement or Cushing's syndrome. By light microscopic examination, the carcinoids manifested an organoid growth pattern, being composed of uniform polygonal cells with central, oval nuclei and finely dispersed chromatin. Immunohistochemical analysis disclosed the presence of cytoplasmic adrenocorticotropic hormone in four cases (three associated with Cushing's syndrome), of somatostatin in seven cases, and of serotonin in one case. Ultrastructurally, these tumors generally showed short, blunt, interdigitating cell processes; focal, scanty basement membrane material; infrequent but well-formed junctional complexes; moderate to large numbers of dense-core granules; and lipoautophagosomes. Six tumors contained small numbers of type I microfilaments, and three demonstrated perinuclear whorls of type II microfilaments. Rough and smooth endoplasmic reticulum was well developed in each tumor, the smooth form being prominent in cases with clinical Cushing's syndrome.

Adrenocorticotropic Hormone↗
PubMed1984

Malignant peripheral nerve sheath tumors in childhood.

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon sarcoma in the pediatric population; however, its presence should be considered in a child with an enlarging or painful soft-tissue mass. Diagnosis of this neoplasm depends on either the demonstration of its origin within a peripheral nerve or the association with a contiguous neurofibroma. We have identified 16 cases of MPNST involving children 16 years of age or less, which represent 12.8% of the total cases seen at the Mayo Clinic. Most of the lesions arose in children with von Recklinghausen's disease and were associated with a contiguous neurofibromatous component. The mean survival of patients who were known to have died of tumor was only 1.8 years. This sarcoma requires prompt aggressive therapy utilizing wide surgical excision. Because of the association of MPNST with von Recklinghausen's neurofibromatosis, a careful workup and family history should be obtained for the potential prognostic value and for the purpose of genetic counseling.

Adolescent↗
PubMed1984

Ectopic secretion of a growth hormone-releasing factor. Report of a case of acromegaly with bronchial carcinoid tumor.

Rarely, acromegaly is produced by neuroendocrine neoplasms elaborating a substance similar to or identical with growth hormone-releasing factor. This report reviews the cases described to date and presents the clinicopathologic features of a patient with acromegaly, mild sellar enlargement, and elevated growth hormone levels associated with a large bronchial carcinoid tumor. Normalization of serum growth hormone levels and regression of acromegaly followed resection of the bronchial tumor, which was shown, by bioassay and immunocytochemistry, to contain a growth hormone-releasing factor.

Acromegaly↗
PubMed1984

Pituitary thyrotropic adenoma associated with congenital hypothyroidism. Report of two cases.

Two patients with congenital hypothyroidism and thyroid-stimulating hormone-secreting pituitary adenomas are described. Both patients had a history of long-standing, inadequately treated hypothyroidism accompanied by markedly elevated levels of serum thyroid-stimulating hormone. Pituitary tissue, obtained at autopsy in the first patient and at surgery in the second, disclosed a thyrotropic adenoma. Immunocytochemical studies with anti-thyroid-stimulating hormone antisera showed both tumors to be strongly immunoreactive. Such thyrotropic adenomas of the pituitary gland are presumed to occur as the result of protracted pituitary stimulation secondary to long-standing thyroid deficiency.

Adenoma↗
PubMed1984

A case for hypothalamic acromegaly: a clinicopathological study of six patients with hypothalamic gangliocytomas producing growth hormone-releasing factor.

We report the histological, ultrastructural, and immunocytochemical features of six hypothalamic gangliocytomas associated with pituitary GH cell adenomas and/or acromegaly. In four patients, the gangliocytoma was intrasellar, and no hypothalamic investigation was performed; in two patients, autopsy confirmed hypothalamic involvement. Four patients had a gangliocytoma associated with pituitary GH cell adenoma and acromegaly; electron microscopy demonstrated an intimate association between neurons and adenomatous GH cells. One patient had a gangliocytoma and a GH cell adenoma but no clinical evidence of acromegaly. In the sixth patient, clinical and biochemical acromegaly was manifest, but no pituitary adenoma was demonstrated. Using immunocytochemistry, human pancreatic tumor GRF (hptGRF-40) was localized in the majority of neurons of all six gangliocytomas. The pituitary adenomas and nontumorous adenohypophyses were negative for hptGRF-40. In addition, somatostatin, glucagon, and GnRH were demonstrated within some neurons of several tumors; insulin and gastrin stains were equivocal. These findings confirm previous proposals of production of a GRF by such gangliocytomas. While the significance of other peptides found in some of the tumors is uncertain, the presence of hptGRF-40 in neurons of these gangliocytomas supports the theory that GRF excess is the mechanism responsible for over-production of GH and provides evidence for a syndrome of hypothalamic acromegaly.

Acromegaly↗
PubMed1984

Pseudomyxoma peritonei associated with mucinous adenocarcinoma of the pancreas: CT findings and CT-guided biopsy.

Pseudomyxoma peritonei is a relatively unusual clinical entity in which a large amount of mucinous material slowly accumulates in the peritoneal space. It occurs in association with a ruptured primary mucinous adenocarcinoma, usually of the appendix or ovary but rarely of the colon, stomach, or uterus. The subject of this case report is the association of pseudomyxoma peritonei with a primary mucinous adenocarcinoma of the pancreas, which, to our knowledge, has not been previously recorded in the literature.

Adenocarcinoma, Mucinous↗
PubMed1984

Leukoencephalopathy in Waldenström's macroglobulinemia. Immunohistochemical and electron microscopic observations.

The clinical and pathologic features of a case of Waldenström's macroglobulinemia with leukoencephalopathy are reported. Multiple cerebral foci of demyelination, accompanied to a lesser extent by axonal degeneration, were associated with perivascular infiltrates of plasmacytoid lymphocytes and with permeation of the white matter by macroglobulins. Immunohistochemical studies demonstrated a predominance of IgM kappa within the blood plasma, in cerebral blood vessel walls, in the foci of demyelination, and within perivascular histiocytes. Electron microscopy disclosed the presence, in macrophages and pericytes, of membrane-bound cytoplasmic inclusions consisting of tubular arrays, suggestive of cryoglobulin deposits. We hypothesize that the high serum levels of macroglobulins accompanied by lymphoplasmocytic infiltrates may, either by way of viscosity-related ischemia, or by a direct toxic effect, have caused abnormal vascular permeability, infiltration of the cerebral parenchyma by paraproteins, and, ultimately, focal degeneration of the white matter.

Demyelinating Diseases↗
PubMed1983

Melanotic neuroectodermal tumor of infancy. A review of seven cases.

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare, usually benign, pigmented neuroectodermal tumor which most often involves the maxilla. The authors reviewed seven cases of MNTI, with patient ages of our patients ranged from nine weeks to 18 months; six of the seven were less than six months old at initial diagnosis. Four patients were males, and all were white. One tumor each was located in the femur, the temporal bone, and the epididymis; the remaining lesions occurred in the maxilla. Three of the four maxillary tumors recurred locally; the epididymal and femoral tumors metastasized. Two of these cases had unique clinical or pathologic features. The case of the femoral tumor is remarkable in that it is the first reported one of MNTI presenting in a long bone. This tumor was aggressively malignant; within two months after its discovery, a large mass of similar tumor was formed in the pelvis, and the tumor resulted in the patient's death. To the authors' knowledge, the case of the temporal bone tumor is the first one of MNTI in which neuronal differentiation of the neuroblastic cells is convincingly demonstrated. This finding provides additional evidence in support of the neuroectodermal theory of origin of these neoplasms.

Female↗
PubMed1983

Postirradiation neurofibrosarcoma.

A known risk of radiation therapy is the induction of secondary neoplasms, most commonly osteosarcoma and fibrosarcoma. A recent addition to the list of postirradiation neoplasms is neurofibrosarcoma, a Schwann cell or fibroblastic malignancy arising in peripheral nerves, often associated with von Recklinghausen's disease. In a clinicopathologic review of 109 patients with neurofibrosarcoma seen at the Mayo Clinic from 1912 to 1981, the tumors in 12 cases were found to originate in areas that had previously been irradiated for benign or malignant disease. Seven of the 12 patients demonstrated stigmata of von Recklinghausen's disease. The mean latency period between irradiation and clinical presentation of the sarcoma was 15.6 years (range, 5-26 years). Eight patients experienced at least one recurrence; metastases were present in two, and nine patients died of their disease. The mean interval between initial diagnosis and death was 3.4 years. In summary, neurofibrosarcoma may arise secondary to radiation; animal studies on the effects of radiation on peripheral nerves support this concept. It is the authors' opinion that patients with von Recklinghausen's disease should not be unnecessarily irradiated, and that those who do receive radiation therapy should be carefully observed for the development of secondary neurofibrosarcoma.

Adult↗
PubMed1983

Primary neuroendocrine carcinomas of the skin (Merkel cell tumors). A clinical, histologic, and ultrastructural study of thirteen cases.

Neuroendocrine carcinomas of the skin have recently been recognized, and clinicopathologic information on these tumors is accumulating rapidly. We studied 13 such lesions by light and electron microscopy, and eight were subjected to immunohistochemical analysis. The ages of the patients (five women and eight men) ranged from 24 to 84 years. Nine patients had neoplasms occurring in sun-exposed areas; one patient had metachronous symmetric lesions on the arms, and another had antecedent hypohidrotic ectodermal dysplasia. Eight tumors metastasized, and six spread to regional or distant lymph nodes. Three patients died with visceral metastases to the liver, bones, and brain. All patients had their primary tumor confined to the corium and subcutaneous tissue without involvement of overlying epidermis. Tumor cells were round and uniform in size, with delicate nuclear chromatin and a high mitotic rate. An organoid growth pattern was seen in all tumors, with focal trabeculation and rare rosette formation. Ultrastructurally, peripheral cytoplasmic dense-core granules were evident, and perinuclear filament whorls could be seen in all 13 tumors. The latter feature was stable, even in specimens taken from paraffin blocks for electron microscopy. Immunoperoxidase studies failed to reveal serotonin, calcitonin, or adrenocorticotrophin within tumor cells.

Adenocarcinoma↗