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Biomedical subjects

A H Mehregan

Publications and source records attributed to A H Mehregan.

At least 19 recordsLinked to original sources
PubMed1992

Malignant blue nevus: a report of eight cases.

Malignant blue nevus is uncommon compared to its benign counterpart and is regarded as a rare form of malignant melanoma. We report the clinical and histological findings in eight cases. Histologically, all eight specimens showed no epidermal involvement and had contained within or were adjacent to portions of blue nevus or cellular blue nevus. Proliferation of bundles of bipolar spindle shaped cells with marked cellular atypia, mitotic figures, foci of necrosis, and inflammatory cell infiltrate were noted. Two of the cases were studied by DNA flow cytometry and the populations of tumor cells were found to be diploid. Two cases have died secondary to metastasis. Although malignant blue nevi may not behave as aggressively as nodular malignant melanoma, they have definite potential to do so and therefore should be removed by wide surgical excision.

Adolescent↗
PubMed1992

Tinea versicolor: histologic and ultrastructural investigation of pigmentary changes.

A comparative histopathologic study is made between the hypopigmented and hyperpigmented skin lesions of pityriasis versicolor and normal skin areas utilizing histochemical stains and electron microscopy. There were no differences found between the population of Dopa-positive melanocytes within the hypopigmented and hyperpigmented lesions and the normal skin areas. The total epidermal pigmentation was diminished in hypopigmented lesions. The keratin layer was found to be significantly thicker in hyperpigmented lesions and contained more organisms. In hypopigmented lesions, melanocytes contained fewer and smaller melanosomes and exhibited signs of degenerative cellular changes.

Cell Count↗
PubMed1992

Benign lymphangioendothelioma: report of 2 cases.

Benign lymphangioendothelioma is an acquired vascular proliferation clinically appearing as well-demarcated, pink to red-brown macules or plaques. Histologically, numerous endothelial-lined channels are found infiltrating throughout the dermis. Recognition and differentiation from malignant vascular tumors is essential. We report 2 cases of benign lymphangioendothelioma. One of these lesions is unique in its presentation as a subcutaneous nodule. The other is also unusual, as it resolved spontaneously.

Female↗
PubMed1992

Epithelioid cell histiocytoma. A clinicopathologic and immunohistochemical study of eight cases.

BACKGROUND: Epithelioid cell histiocytomas histologically resemble the intradermal form of Spitz nevus. OBJECTIVE: We have studied eight patients with epithelioid cell histiocytoma. METHODS: In addition to the routine stains, histologic sections were prepared by immunohistochemical techniques for S-100 protein, HMB-45, vimentin, alpha 1-antitrypsin, and common leukocyte antigen. RESULTS: Epithelioid cell histiocytoma is characterized by proliferation of angulated epithelioid cells with abundant eosinophilic cytoplasm. Immunostaining for S-100 protein and HMB-45 were negative. The majority of cells had positive reactions to staining for vimentin and alpha 1-antitrypsin. Approximately 20% to 25% of cells also gave positive reactions to common leukocyte antigen. CONCLUSION: Immunostainings are useful in the differential diagnosis of epithelioid cell histiocytoma from the intradermal form of Spitz nevus.

Adult↗
PubMed1979

Alarm reaction of pilosebaceous apparatus.

A series of histologic changes involving the pilosebaceous structures are described under the term "alarm reaction." The follicular manifestation of this phenomenon is characterized by regression of hair matrix, forming a well-defined nest of small basaloid cells found in various parts of the follicular canal. The sebaceous glands either become undifferentiated, forming a solid mass of stratified squamous epithelium, or the sebaceous lobules are taken into the follicular canal and into the surface keratin layer.

Adult↗
PubMed1979

Pili multigemini. Report of a case in association with cleidocranial dysostosis.

A patient with cleidocranial dysostosis developed extensive pili multigemini over the heavily bearded chin and cheek areas. Histological examination of serial sections revealed complicated follicular structures forming from two to as many eight hair shafts. Each hair is formed by a single branch of dermal papilla which is surrounded by all layers present in a normal follicle except for the outer root sheath cells. The outer root sheath surrounds the entire follicle. Irregularities in configuration of the hairs, longitudinal grooving and areas of bifurcation and re-adhesion of the hair shafts are demonstrated.

Adult↗
PubMed1979

The dermatopathology of Cowden's syndrome.

During the past 2 years we have studied eighty-nine biopsy specimens from nineteen patients with Cowden's syndrome. Among fifty-three facial lesions, twenty-nine were trichilemmomas. Twenty-three of the others were consistent with trichilemmoma, showed a non-specific benign verrucous acanthoma, or were not diagnostic; one was a blue naevus. All fourteen oral mucosal biopsy specimens were benign fibromas. Nineteen of twenty-two biopsy specimens from the hands and feet showed the pattern of benign keratosis. Multiple trichilemmomas were found in all patients with Cowden's syndrome, but at times several biopsy specimens were required before a diagnostic picture was uncovered. All patients with multiple facial trichilemmomas were found to have Cowden's syndrome. The combination of multiple facial trichilemmomas, oral fibromas, and benign acral keratoses enables one to diagnose Cowden's syndrome at a stage before serious internal complications develop.

Abnormalities, Multiple↗
PubMed1979

Benign follicular neoplasias.

The generality of benign epithelial neoplasias of follicular origin or with differentiation toward follicular structures is briefly reviewed. Recently delineated examples of this group are more extensively discussed.

Adenoma↗
PubMed1979

Basal cell epitheliomas in usual and unusual sites.

2,126 consecutively diagnosed basal cell epitheliomas (BCE) were studied for unusual sites of occurrence. A small number of BCE occurred in unexpected locations and presented some difficulty in clinical diagnosis.

Adolescent↗
PubMed1979

Porokeratosis of Mibelli. A report of two unusual cases.

2 cases are reported with unusual manifestations of porokeratosis of Mibelli. In 1 case multiple atrophic facial lesions resembled plaques of chronic discoid lupus erythematosus. The second case exhibited extensive cutaneous involvement in the form of hyperkeratotic lesions in linear configuration.

Adolescent↗
PubMed1978

Cutis laxa (generalized elastolysis). A report of four cases with autopsy findings.

Four children with cutis laxa (generalized elastolysis) are reported. The first three cases were siblings from a Canadian Indian family and the fourth case was the only affected child in an American Black family. Loose and sagging skin folded over the face, neck and trunk, gave a premature senile appearance. Post-mortem examination was performed on the first three cases. The most common and serious visceral involvement was development of pulmonary emphysema. This was present in two autopsied cases and was demonstrated by chest X-ray in the fourth case. Other abnormalities included large inguinal and perineal hernia, rectal diverticulum and multiple diverticulae of the urinary bladder.

Abnormalities, Multiple↗