Primary Amelanotic Malignant Melanoma of the Anorectal Region Presented with Pulmonary Metastasis—A Case Report—

Abstract

We report a case of primary amelanotic malignant melanoma of the anorectal region presented with pulmonary metastasis. The patient, a 53-year-old woman, was referred to us because of an abnormal chest X-ray finding during a physical examination. A diagnosis of amelanotic malignant melanoma was made by histopathological studies after surgery for a solitary nodule in the left upper lobe of lung. An additional lower gastrointestinal endoscopy biopsy confirmed the diagnosis of primary amelanotic malignant melanoma of the anorectal region. Despite laparoscopic rectal amputation and bilateral lateral lymph node dissection (D3), the patient died 25 months after surgery. Primary amelanotic malignant melanoma of the anorectal region is relatively rare, and no treatment has been established. Further accumulation of clinical cases and establishment of treatment methods are desirable.