Amelanotic melanoma (AM) is a rare and aggressive variant of cutaneous melanoma characterised by the absence of pig-mentation, often leading to delayed diagnosis due to its ability to mimic benign inflammatory or neoplastic conditions. Wereport the case of a 68‐year‐old woman presenting with a slowly enlarging, erythematous, mildly scaling patch on the left arm,previously misdiagnosed and treated as eczema and mycosis for 3 years without improvement. Dermoscopy revealed few non‐specific polymorphic vessels, while line‐field confocal optical coherence tomography (LC‐OCT) demonstrated hyperkeratosisand atypical dark cells throughout the epidermis with dermal invasion. Histopathological examination confirmed amelanoticmelanoma (Breslow thickness 1.1 mm, Clark level IV, pT2a). Wide local excision and sentinel lymph node biopsy wereperformed, with no evidence of metastasis. This case highlights the diagnostic challenge posed by eczema‐like AM andunderscores the importance of maintaining a high index of suspicion and performing biopsy in persistent, treatment‐resistanterythematous lesions.
Eczema‐Like Amelanotic Melanoma: A Diagnostic Challenge
Janowska, Agata;Maggiora, Andrea della;Mori, Nicolò;Romanelli, Marco;Dini, Valentina;Naccarato, Antonio Giuseppe;Scatena, Cristian
2026-01-01
Abstract
Amelanotic melanoma (AM) is a rare and aggressive variant of cutaneous melanoma characterised by the absence of pig-mentation, often leading to delayed diagnosis due to its ability to mimic benign inflammatory or neoplastic conditions. Wereport the case of a 68‐year‐old woman presenting with a slowly enlarging, erythematous, mildly scaling patch on the left arm,previously misdiagnosed and treated as eczema and mycosis for 3 years without improvement. Dermoscopy revealed few non‐specific polymorphic vessels, while line‐field confocal optical coherence tomography (LC‐OCT) demonstrated hyperkeratosisand atypical dark cells throughout the epidermis with dermal invasion. Histopathological examination confirmed amelanoticmelanoma (Breslow thickness 1.1 mm, Clark level IV, pT2a). Wide local excision and sentinel lymph node biopsy wereperformed, with no evidence of metastasis. This case highlights the diagnostic challenge posed by eczema‐like AM andunderscores the importance of maintaining a high index of suspicion and performing biopsy in persistent, treatment‐resistanterythematous lesions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
