Case Report: Imaging findings in sneaky subungual amelanotic melanoma

We report a rare case of solitary subungual malignant melanoma in a female patient who presented with a misaligned nail without accompanying pigmentary changes. The absence of typical clinical and imaging features delayed definitive diagnosis. Both magnetic resonance imaging (MRI) and ultrasound (US) initially suggested a benign lesion, favoring subungual telangiectatic granuloma. However, histopathology ultimately confirmed subungual melanoma with negative Human Melanoma Black-45 (HMB-45) immunostaining. Amelanotic melanomas are particularly prone to misdiagnosis or delayed recognition due to their lack of visible pigmentation. We present a detailed analysis of the imaging and pathological findings, highlighting specific ultrasound characteristics, with the aim of providing a valuable reference for the clinical diagnosis and management of such uncommon cases.