Pilomatricoma with bullous‐like/anetodermic appearance: Possibly associated with matrix metalloproteinases

Abstract

Pilomatricoma, a benign cutaneous tumor, sometimes demonstrates a bullous-like or anetodermic appearance. However, the pathogenesis of the formation of bullous-like/anetodermic appearance is not well characterized. We herein report three cases of pilomatricoma with bullous-like/anetodermic appearance and three cases of pilomatricoma with ordinary

Pseudobullous pilomatricoma: A rare variant of pilomatricoma

“…It subsequently induces the dilation of lymphatic vessels and subsequent leakage of lymphatic fluid, producing a bullous appearance. 3 , 6 In our case, both lymphatic dilatation and lack of collagen fibres could be demonstrated. Therefore, we speculated that compression of the lymphatic vessels and long‐term mechanical irritation by the tumour might contribute to the occurrence of the bulla.…”

“…Some reports suggest that the elastinolytic enzymes produced by tumour cells and lytic products may cause the decline of elastic fibres and demolition and dilation of the lymphatic vessels, causing lymph fluid accumulation in the dermis, and consequently forming a bullous appearance. 6 However, the more widely accepted hypothesis is that the tumour nodule growth causes hindrance in the lymphatic vessels and congestion of lymphatic fluid. It subsequently induces the dilation of lymphatic vessels and subsequent leakage of lymphatic fluid, producing a bullous appearance.…”

High‐frequency ultrasonography of bullous pilomatricoma

“…The shoulder and upper arm are the most common locations . Histologically, it is characterized by the presence of interstitial edema, sparse collagen, and elastic fibers, and the infiltration of macrophages in the dermis overlying the tumor . Two theories have been proposed to explain its pathogenesis.…”

“…The growth of the tumor may cause obstruction of lymphatic vessels with subsequent leakage of lymphatic fluid and edema of the dermis. The second theory suggests that the presence of matrix metalloproteinases (MMP‐9 and MMP‐12), released by fibroblasts and inflammatory cells surrounding the tumor, may be associated with the degradation of elastic fibers and collagen . While dermatologists are familiar with the clinical diagnosis of pilomatricomas, this particular variant can represent a diagnostic challenge.…”

Dermoscopic and Immunohistochemical Observations in Anetodermic Pilomatricoma: A Case Report

“…Pilomatricoma, or calcifying epithelioma of Malherbe, is a benign cutaneous neoplasm originating from hair matrix cells. Anetodermic, pseudobullous, or lymph angiectatic pilomatricoma is a rare variant, and, to-date, approximately 30 cases have been reported (1)(2)(3)(4)(5). Although dermoscopy is helpful to diagnose non-anetodermic pilomatricoma (6)(7)(8)(9), its application has been documented in only one case of anetodermic pilomatricoma (1).…”