Abstract

We present the case of a 62-year-old male with a 1 cm pink crusted plaque on the right anterior proximal thigh of several months duration. Histopathologic examination of a subsequent shave biopsy revealed the lesion to be predominantly composed of buds of basaloid epithelium with stromal retraction artifact consistent with a superficial basal cell carcinoma (BCC). However, towards one edge of the specimen, focal compact orthokeratosis and low papillomatous epidermal hyperplasia containing foci of basaloid epithelium with overlying differentiation towards the inner root sheath and associated trichohyalin granules consistent with ‘bulboma’ was also noted. ‘Bulboma’ is recently proposed moniker for a solitary acanthoma exhibiting differentiation toward the lower segment of the hair follicle at the level of the bulb. To date, perhaps given the rarity of this entity, we report the first case of bulboma in close association with a superficial BCC. As this lesion was focally contiguous with the basal cell carcinoma, these findings raise the possibility of either a collision lesion or even a bulboma with malignant transformation into a superficial BCC. We present this case to raise awareness that, while “bulboma” itself may be benign, and although further investigation is warrated, it may also be involved with, arise in association with, or perhaps even demonstrate transformation into a malignant follicular neoplasm, including BCC.