Folliculosebaceous Cystic Hamartoma With Spindle Cell Lipoma-Like Stromal Features

Abstract

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.

Bright lobulated tumor on the face in a newborn

“…These findings suggested the possibility that adipocytes and other mesenchymal components in FSCH originated from nestin-positive multipotent stem cells. 9,10 O RCI D Ana María Sáenz https://orcid.org/0000-0002-6660-2835…”

Cutaneous spindle cell adenolipoma with eccrine and apocrine differentiation

“…Neurofibroma can be excluded given that the spindle cells in SCAL are positive for CD34 and negative for S100 . Although folliculosebaceous cystic hamartoma with SCL‐like stroma shows a similar stromal component to SCAL, the epithelial component consists of proliferating sebaceous glands radiating from cystically dilated follicular structure(s) . Mixed tumors have more numerous epithelial structures with a background of commonly chondroid stroma.…”

Folliculosebaceous neoplasms: A review of clinical and histological features

“…Adjacent to the lobules is the mesenchymal proliferation, which may consist of a variety of elements including collagen, mature adipose tissue (frequently present), smooth muscle, neural tissue and often increased vascularity. A CD34 + spindle cell proliferation may predominate in some lesions and, in addition to the mature adipose tissue, may be associated with ropy collagen simulating a spindle cell lipoma . Increased stromal mucin may also be seen.…”

“…A CD34 + spindle cell proliferation may predominate in some lesions and, in addition to the mature adipose tissue, may be associated with ropy collagen simulating a spindle cell lipoma. 104 Increased stromal mucin may also be seen.…”