Frequent Detection of Androgen Receptors in Spindle Cell Lipomas: An Explanation for This Lesion's Male Predominance?

Abstract

Context.—Spindle cell lipoma (SCL) is a tumor with marked male predilection. We discovered one SCL that exhibited strong immunoreactivity for androgen receptors (ARs) in the spindle cells. Objective.—The hypothesis was that ARs in SCLs would not be rare and that all or nearly all SCLs would be AR positive, perhaps explaining its male predominance. Design.—Twenty-eight cases of SCL (22 men, 6 women) and a control group of 20 conventional lipomas (10 men, 10 women) were stained with monoclonal AR antibody (1: 150; Dako, Carpinteria, Calif) using the Ventana Discovery. Only nuclear reactivity was considered positive, as noted in prostate controls. Cell types (fat, spindle cells) and extent of staining were recorded as rare, considered negative, focal (1+), or diffuse (2+/3+). Results.—All 22 cases of SCL in men were positive for ARs. Twenty showed diffuse (2+/3+) reactivity mainly in the spindle cells. Of the 6 SCLs in women, 1 was AR negative, 1 showed a 3+ reaction in the spindle cells, and 4 had weak (1+) staining of spindle cells. Overall, 96% of SCLs were AR positive, including 83% of SCLs in women. Seventy percent of conventional lipomas showed positive staining in fat, but only 2 showed 2+ staining. In the rest, staining was rare or weak (1+). Conclusions.—Nearly all SCLs exhibited AR reactivity. However, the presence of ARs in a substantial percentage of ordinary lipomas and in SCLs in females mitigates against the hypothesis that AR reactivity alone can explain the marked male predominance of SCL.

Extramammary myofibroblastoma of the oral cavity

“…Though available data are limited to a few small case series and some case reports, cases of MF with positivity for a single, a combination of two, or all three steroid hormone receptors have been reported. 5,9,[13][14][15][16][17][18] Conversely, 96% of SCLs are AR+, 19 and PR expression in SCL is rare. 20 We did not find any reports of SCL with isolated PR positivity.…”

Spindle cell lipoma of the buccal mucosa: Uncommon finding in an older adult

“…Trauma has been proposed as an aetiopathological factor in a subset of oral lipomas, usually associated with mastication. Other implicated contributors to lipoma formation include hormonal influences, herniation of the buccal fat pad and chromosomal aberrations (particularly 13q) 10,11 . There is also an apparent correlation of adipocytic lesions with obesity; however, reduced caloric consumption does not seem to render any effect on lesional size 12 …”

“…Other implicated contributors to lipoma formation include hormonal influences, herniation of the buccal fat pad and chromosomal aberrations (particularly 13q). 10,11 There is also an apparent correlation of adipocytic lesions with obesity; however, reduced caloric consumption does not seem to render any effect on lesional size. 12 The clinical differential diagnosis of papular lesions on the buccal mucosa is diverse and commonly includes fibroma and mucocele, and less often with other benign and malignant salivary gland disorders, epidermal cyst, solitary fibrous tumour, schwannoma, Kimura disease, neurofibroma, follicular lymphoid hyperplasia, lymphoma and metastatic disease.…”

Spindle Cell Lipoma with Ossification Mimicking Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma: A Case Report

“…4,5 Approximately 80% of SCL patients are men, often in their 50 s. 4 Male predominance may be explained in part by the presence of androgen receptors in SCLs and thus the potential need of these receptors for tumor growth. 9 Interestingly, women more often develop SCLs in atypical locations and at younger ages compared to men. 2 The reported average SCL size is less than 5 cm, although SCLs exceeding 15 cm have been described.…”