title: Folliculosebaceous Cystic Hamartoma With Spindle Cell Lipoma-Like Stromal Features.
abstract: Folliculosebaceous cystic hamartoma is a distinctive cutaneous hamartoma composed of follicular, sebaceous, and mesenchymal components. The lesions are most commonly found on the face and scalp of young adults, with approximately 30% occurring in the nasal or paranasal regions of the face. The clinical differential diagnoses are extensive and include epidermoid cyst, dermal nevus, soft fibroma, and adnexal tumors including sebaceous neoplasms. Here, the authors present a case of a 24-year-old man who presented for evaluation of an asymptomatic growth on the nose, which had slowly enlarged over 9 years. On examination, there was a 0.6 cm dome-shaped flesh-colored papule on the nasal bridge. The clinical differential included dermatofibroma versus intradermal nevus. A shave biopsy was performed, and histological examination of the sections showed a proliferation of multiple enlarged and irregular-appearing sebaceous glands attached to a cystic follicular structure. The associated dermal mesenchymal component consisted of numerous mature-appearing adipocytes associated with a fibromyxoid stroma, prominent collections of mucin, and bundles of ropey collagen resembling a spindle cell lipoma. This combination of a folliculosebaceous cystic hamartoma with a spindle cell lipoma-like mesenchymal proliferation is unusual and has not been previously reported.
authors.affiliation: *Department of Dermatology, Irvine School of Medicine, University of California, Irvine, CA; †Department of Dermatology, Irvine Medical Center, University of California, Irvine, CA; and ‡Department of Dermatology, Kaiser Permanente, Los Angeles, CA.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Nguyen
authors.forename: Hadas
authors.initials: H
authors.lastname: Skupsky
authors.forename: David
authors.initials: D
authors.lastname: Cassarino
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D005497:Follicular Cyst / Q000473:pathology*; D006222:Hamartoma / Q000473:pathology*; D006801:Humans; D008067:Lipoma / Q000473:pathology; D008297:Male; D012627:Sebaceous Glands / Q000473:pathology; D012871:Skin Diseases / Q000473:pathology*; D055815:Young Adult