Folliculosebaceous Cystic Hamartoma with Spindle Cell Lipomatous and Neural Components

Area of Science:

• Dermatopathology
• Cutaneous Oncology
• Surgical Pathology

Background:

• Folliculosebaceous cystic hamartoma is a rare benign skin neoplasm.
• It is characterized by a cystic hamartomatous proliferation of follicular and sebaceous structures.
• Associated mesenchymal elements typically include fibrous stroma, adipocytes, and vascular channels.

Observation:

• A case of a 55-year-old female patient presenting with a cutaneous nodule on the right nasal wing is detailed.
• Microscopic examination revealed a dilated hair follicle with multiple sebaceous glands.
• The lesion was surrounded by a mesenchymal component resembling spindle cell lipoma, with an additional neural component.

Findings:

• The observed mesenchymal component included fibromyxoid stroma, spindle cells, mature adipocytes, and collagen bundles.
• A novel finding was the presence of small nerve bundles within the mesenchymal component.
• This represents the first reported instance of folliculosebaceous cystic hamartoma with combined spindle cell lipomatous and neural features.

Implications:

• This case expands the histopathological spectrum of folliculosebaceous cystic hamartoma.
• Recognizing this rare variant is crucial for accurate diagnosis and appropriate patient management.
• Further research may elucidate the developmental pathways and clinical significance of these combined elements.