Primary anorectal melanomas: an istitutional experience

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Primary melanomas (M) of the rectum and anal canal are rare, accounting for about 1% of invasive tumors in this region.
• These neoplasms present unique diagnostic and therapeutic challenges due to their infrequent occurrence and aggressive nature.

Purpose of the Study:

• To analyze the clinical characteristics, treatment outcomes, and survival rates of patients with primary anorectal melanoma.
• To evaluate the prognostic factors influencing survival in this rare malignancy.

Main Methods:

• Retrospective analysis of 11 patients treated for primary anorectal melanoma between 1973 and 1990.
• Data collected included patient demographics, tumor site and size, presenting symptoms, diagnostic methods, treatment modalities (curative resection vs. palliative care), and survival data.

Main Results:

• The study included 11 patients (5 males, 6 females; mean age 60 years) with melanomas originating in the rectum (4), anus (5), or anorectal junction (2).
• Lesions were predominantly polypoid, averaging 4 cm in size, with symptoms including rectal bleeding and tenesmus.
• Six patients underwent curative resection, with one surviving disease-free for 120 months. Five patients received palliative treatment due to metastases or poor general condition, with a median survival of 4 months.
• Overall median survival was 8 months, with 20 months for the radically treated group and 4 months for the palliatively treated group.

Conclusions:

• Primary anorectal melanoma is a severe prognostic entity, often diagnosed late.
• Aggressive biological behavior and delayed diagnosis contribute to poor outcomes.
• Curative resection, when feasible, significantly improves survival compared to palliative treatment.