Abstract | May 5, 2021
Prolapsed rectal hemorrhoid: A rare presentation of anorectal melanoma
Learning Objectives
- In every case of suspected hemorrhoids, must perform a thorough rectal examination;
- Consult surgery early in the course of treatment to get their expert opinion;
- Have wide variety of differential diagnosis in mind for prolapsed rectal mass;
- Pathology evaluation of all excised masses are necessary to reach to final diagnosis;
- Know the available treatment options for anorectal melanoma.
Introduction:
The anorectal mucosal melanoma accounts for approximately 0.05 percent of all colorectal malignancies and 1 percent of all anal canal cancers. The mucosal melanomas are rare and account for approximately 1 percent of all melanomas. The risk factors for anorectal mucosal melanoma are not known, epidemiologic data suggest that there is an increased risk associated with human immunodeficiency virus infection
Case Presentation:
We had a 39-year-old female with past medical history of chronic anemia presented with lower abdominal pain. Per patient she had noticed worsening of abdominal pain from last 3 days after picking up heavy box. She was having feeling of incomplete evacuation.
She also noticed a mass protruding from rectum. The pain was severe with defecation and also noted blood on tissue paper. The rectal exam showed a large, nodular appearing, firm mass protruding from the rectum, tissue appears to be mottled in color and has purulent discharge- (massive hemorrhoid with partial rectal prolapse). Patient labs showed anemia with Iron deficiency. The rest of exam was benign. General surgery was consulted, patient was taken to operation theater for excision of mass. During operation there was a large lump with flattened base, pedunculated and originating from the anorectal ring. An elliptical incision was made at the stalk and it was deepened through the mucosal layer with a grossly health margin of 5 mm. The patient recovered from surgery and discharged next day home in a stable condition.
Final Diagnosis:
The pathology report showed the ulcerated polypoid malignant melanoma, 9.8 cm tumor was invading muscularis propria, lympho vascular invasion by tumor was present. The patient was immediately called and set up with hematology/oncology for further evaluations
Management:
The treatment recommendations for patients with mucosal melanoma is based on single center retrospective trial. Initial management for locoregionally confined mucosal melanoma is complete wide local surgical resection. Most patients will ultimately develop distant metastatic disease regardless of the achievement of local control. The radiation therapy is the option for inoperable disease. The adjuvant chemotherapy is also an option for extensive disease.
