Cytomorphological Features of Scalp Cylindroma: Insights From Fine Needle Aspiration Cytology.

Cylindroma is a rare benign cutaneous adnexal tumour that commonly occurs on the scalp. Accurate cytological diagnosis can be difficult due to overlap with other basaloid neoplasms. We report a 71-year-old woman presenting with two slowly enlarging scalp nodules. FNAC revealed moderately cellular smears with clusters and acini of basaloid cells with hyperchromatic nuclei and scant cytoplasm, along with a second population of larger cells with vesicular nuclei and moderate cytoplasm. Tumour cell groups were surrounded by abundant hyaline basement membrane-like material. No atypia, mitoses or necrosis were observed. Histopathological evaluation of the excised lesion confirmed the diagnosis of cylindroma. Recognition of these cytomorphological features on FNAC facilitates accurate preoperative diagnosis, guiding appropriate surgical management. This case is notable for highlighting the characteristic FNAC findings of scalp cylindroma, a rarely documented entity, thereby reinforcing its cytological distinctiveness and diagnostic value.