Primary rectal melanoma

Early-Stage Primary Rectal Melanoma: A Case Report

Malignant primary rectal melanomas (PRM) are rare tumors. Their diagnosis is frequently delayed as these lesions are often mistaken for benign diseases, resulting in extremely poor overall survival. Histological evaluation with special immunohistochemical (IHC) stains is often indispensable for a definitive diagnosis. The main treatment for this condition involves surgical resection. Adjuvant therapy has also been long recommended. We discuss the case of a 60-year-old woman who presented with changes in bowel habits, anal pain, and perineal burning with no bleeding. A digital rectal examination revealed a nodular mass extending 5 cm from the anal verge. Rectosigmoidoscopy demonstrated an ulcerated polypoid tumor extending 4 cm from the anal verge and over 5 cm into the lower rectum. Biopsy and IHC tests confirmed the diagnosis of rectal melanoma. The patient was successfully managed with surgery followed by external beam radiotherapy and a complete response was achieved after 10 months of follow-up.

Anorectal Melanoma: An Uncommon Cause of Lower Gastrointestinal Bleeding

Anorectal melanoma (ARM) is a rare, aggressive disease. Given that it presents with local symptoms that resemble other common benign anorectal conditions, ARM is often low on the differential diagnosis. Delayed diagnosis and nonconsensus of treatment options lead to poor prognosis. Here, we report the case of an 85-year-old woman with a history of Irritable bowel syndrome who presented with altered bowel habits and bleeding per rectum. CT revealed a rectal mass with metastatic lesions to the bone, liver, and lungs. Immunohistochemical staining was positive for Human Melanoma Black-45, melanoma antigen recognized by T cells, and SRY-related HMG-box 10. A final diagnosis of ARM was made.

Primary anorectal malignant melanoma with laparoscopic abdominoperineal resection: a case study and review of the relevant literature

ARMM is a disease with a poor prognosis. ARMM is often diagnosed at an advanced stage, and the 5-year survival rate of ARMM is < 20%. Although the number of case reports on ARMM is gradually increasing, the optimal treatment strategy for ARMM remains controversial. We report the case of an 81-year-old woman who had experienced bloody stool for 6 months before her diagnosis and who had been initially diagnosed with hemorrhoids. The pathological diagnosis of a biopsy specimen was malignant melanoma. Other examinations showed no evidence of lymph node or distant metastasis. Based on these results, laparoscopic abdominoperineal resection was performed. Three months later on her first follow-up examination, distant metastasis to the lung and liver was detected. Immunotherapy using Nivolumab was initiated to treat the recurrent disease. We reviewed the characteristics of a total of 1834 ARMM patients described in previous reports on ARMM for which the full text was available on PubMed. We experienced a case of ARMM. The prognosis of ARMM is still poor, regardless of the surgical procedure. Previous studies and our case report suggest that systemic therapy, such as immunotherapy using an anti-PD-1 ligand may be more important than reinforcement of local control for improving the prognosis of ARMM patients.

Primary anorectal melanoma-a rare entity: case report

Anorectal melanoma is a rare disorder. There have only been a few cases reported and there is no consensus of treatment. We report a case of 50-year-old Caucasian man presenting intermittent prolapse of an anorectal mass during 6 months with occasional bleeding. Biopsies came up with the diagnosis of malignant melanoma. No distant metastases were found. He underwent an abdominoperineal resection due to internal sphincter invasion. A second tumour was diagnosed in final histologic examination: a dysplastic rectal polyp invaded by the melanoma (collision tumour). At 12 months of follow up he presented loco-regional recurrence (a single pelvic lymph node) and hepatic metastases. He was included in a study protocol comparing new medical treatments (nivolumab versus ipilimumab or both).