Track
Clinical StudiesAbstract
Folliculosebaceous cystic hamartoma (FSCH) is a rare cutaneous hamartoma composed of epithelial and mesenchymal elements, typically arising on the scalp and face. The epithelial component consists of cystically dilated hair follicles surrounded by sebaceous glands, while the mesenchymal component may contain fibrous stroma, adipocytes, and vascular structures. We identified one FSCH with markedly increased stromal cellularity, characterized by a proliferation of spindle-shaped fibroblasts. Immunohistochemistry (SMA, Desmin, SOX-10) excluded smooth muscle and neural differentiation. To assess the potential correlation between stromal cellularity and clinical features including age, sex, and location of the lesion, we reviewed seven previously diagnosed FSCHs from 2020 to 2025, grading stromal cellularity as mild, moderate, and marked. Patient ages ranged from 38–67 years; three were females and four males. Lesions were located on the nose (n=3), cheek, preauricular area, axilla, and shoulder. Of the seven cases, one showed marked stromal cellularity, two moderate, and four mild. The markedly cellular case occurred in the youngest patient, a 38-year-old woman with a lesion on the left nasal ala. Hypercellular stroma in FSCH may mimic other lesions and result in misdiagnosis. To our knowledge, no prior studies have examined stromal cellularity in FSCH in relation to clinical data.