Bullous pilomatricoma: A rare variant resembling bouncy ball

Abstract

Pilomatricoma (pilomatrixoma) or calcifying epithelioma of Malherbe, is a tumor with differentiation toward hair cells, particularly hair cortex cells. It frequently presents as a firm, deep-seated nodule that is covered by normal skin. Bullous pilomatricoma is an unusual clinical variant. Reports on bullous variant of pilomatricoma is sparse, and only 17 cases have been reported world-wide until date out of which only two cases are reported from India. We present a report of a 17-year-old female with a solitary reddish semi-transparent blister over her right upper arm since 3 months resembling a bouncy ball. Histopathology revealed tumor nests of basophilic cells and eosinophilic shadow cells, which are consistent with pilomatricoma.

Pilomatricoma: An Unusual Presentation

“…The overlying skin normally has a bluish discoloration. Although lesions with bullous changes on the overlying skin are very rare, they have been reported 1 , 2 , 3 . Herein, we report a case of bullous pilomatricoma to enhance the recognition and proper management of this variant, which represents a particular diagnostic challenge.…”

“…Reports on bullous pilomatricoma are limited. To date, a total of 18 cases have been published 1 . Bullous pilomatricoma has a predilection for the shoulder and upper arm regions, predominantly affecting women aged 10 to 20 years.…”

A rare variant of pilomatricoma: pseudobullous pilomatricoma

“…Another theory is that, with the impact of the elastolytic enzymes secreted from the tumor cells and inflammatory cells, the lymph veins become damaged and dilated (9). Because the bullous areas detected in the PM are filled with lym-phatic liquid, some authors use the term pseudobulla (5,6,10).…”

Bullous pilomatricoma: a rarely reported variant of pilomatricoma

“…Pilomatricomas are benign cutaneous adnexal tumors with hair matrix differentiation [1][2][3]. Representing 20% of hair-follicle tumors, pilomatricomas tend to present as solitary, non-tender nodules on the head, neck, or upper extremities in females under the age of 20 [1].…”

“…Pilomatricomas are benign cutaneous adnexal tumors with hair matrix differentiation [1][2][3]. Representing 20% of hair-follicle tumors, pilomatricomas tend to present as solitary, non-tender nodules on the head, neck, or upper extremities in females under the age of 20 [1]. Pilomatricomas are precipitated by mutations in CTNNB1, a gene encoding β-catenin, which is linked with upregulated hair follicle differentiation and decreased apoptosis [1,4].…”