Introduction

Nevus sebaceus of Jadassohn is a benign congenital hamartoma involving the pilosebaceous–apocrine unit. Although sebaceous and apocrine elements are well documented in these lesions, the coexistence of sebocytes and calcifications within the lumina of apocrine glands appears to be exceptionally rare.

Case report

We describe a 50-year-old man who presented with a long-standing linear verrucous plaque on the forehead. Histopathological examination revealed papillomatosis, acanthosis, and proliferation of sebaceous and apocrine structures, with sebocytes identified within the lumina of apocrine glands, accompanied by discrete intraluminal calcifications. The lesion was surgically excised, followed by reconstructive surgery, with a satisfactory cosmetic outcome.

Conclusions

Based on the close embryologic relationship within the pilosebaceous-apocrine unit, transfollicular sebaceous extrusion, and theories of glandular degeneration and dystrophic mineralization, we propose developmental, mechanical, and degenerative mechanisms that may underline this coexistence. This case broadens the morphologic spectrum of nevus sebaceus of Jadassohn and highlights its potential for adnexal architectural intermingling.