C-KIT Mutant Anorectal Melanoma: Diagnostic Pitfalls and Treatment Perspectives

Abstract

Mucosal melanomas (MM) are an uncommon and aggressive subtype of melanoma that differ from cutaneous forms in both genetic profile and clinical behavior. Anorectal melanoma (ARM), in particular, is characterized by its rapid progression and distinct molecular alterations, notably mutations in the c-KIT gene. These mutations may serve as potential therapeutic targets and open the door to individualized treatment approaches, especially in the metastatic setting where standard therapeutic options are limited. We report the case of a 72-year-old female admitted to our hospital with a rectal mass noticed during defecation and associated rectal hemorrhage. Vital signs on admission were within normal limits. Histological and molecular biology investigations confirmed ARM harboring a c-KIT mutation. The patient received systemic imatinib therapy targeting this molecular alteration, which led to stable disease on imaging and clinical improvement after three months of follow-up. This case study highlights the clinical significance of c-KIT mutations in ARM, emphasizing their diagnostic, prognostic, and therapeutic implications.