Acquired Smooth Muscle Hamartoma With Sebaceous Component
TLDR The patient has a rare skin condition that shows features of two known disorders.
An 18-year-old male presented with a pigmented and hypertrichotic plaque on his left hemifacial area, which had been developing over a year. The lesion, following a linear Blaschkoid path, also included papular lesions but did not exhibit the pseudo-Darier sign. Histological examination revealed an increased number of disorganized smooth muscle bundles in the dermis, abundant sebaceous glands, and numerous hair follicles at various stages of development. With only 25 cases of acquired smooth muscle hamartoma (ASMH) reported previously, this case is notable for its prominent sebaceous component. The findings suggest that this lesion represents an intermediate condition within a spectrum that includes ASMH and folliculosebaceous cystic hamartoma, with this case displaying characteristics of both conditions.
