A case report of anorectal malignant melanoma with mucosal skipped lesion

Primary anorectal amelanotic melanoma with liver, lungs and lymph nodal metastases

Anorectal melanoma (ARM) is an exceedingly rare and very aggressive malignancy. It originates from the melanocytic cells in the anorectal mucosa, which produces melanin. Other mucosal melanomas commonly found in the mucosa of the oral cavity, vulvovaginal, pharynx and urinary tract. Patients usually present with bleeding per rectum, perianal pain and difficulty in defaecation. Distinction of primary anorectal melanoma from other tumours of this region is difficult because of the lack of common imaging features. MRI is the modality of choice for its better tissue characterisation and resolution. There is no standard treatment protocol available mainly due to scarcity of data. Surgery is the mainstay therapy. Herein we present a case of a male patient in his 30s who presented with rectal bleeding and perianal pain. Haematological analysis revealed normocytic normochromic anaemia. MRI detected a mass lesion in the anorectal region. Contrast enhanced CT revealed multiple metastases in the liver, lungs, periportal, mesorectal and inguinal lymph nodes. The diagnosis of the ulcerated anorectal melanoma was established on histopathological examination. The patient underwent abdominoperineal resection (APR) followed by chemotherapy. Afterward the patient presented to the emergency room with respiratory distress for which he was on ventilator support. Sadly, the patient died after four days.

Metastatic Anorectal Melanoma Presenting as Seizures: An Infrequent Culprit

Anorectal malignant melanoma is a rare culprit of malignancies in the anorectal region. With a presentation that mimics the vastly more common colorectal tumours, clinical misdiagnosis and diagnostic delays often occur, contributing to a dismal prognosis. The authors report a case of metastatic anorectal malignant melanoma presenting as seizures. Though our standard diagnostic pathway for suspected anorectal malignancies was followed, and despite the patient having computerized tomography (CT) of the head earlier, this presentation nonetheless led to a prolongation of time needed to reach histological diagnosis and delay in commencing definitive treatment. It also highlights the paucity of research into the pathophysiology and management of this infrequent but aggressive disease, and the need for raising awareness about this condition to the medical community so that it is considered as a plausible differential diagnosis from the outset and diagnostic pathways adjusted accordingly.

Malignant Melanoma of Anorectum: Two Case Reports

Malignant melanoma of the anorectum is a rare disorder. Patients often present with local symptoms similar to benign diseases. The prognosis is very poor, and almost all patients die because of metastases. We report 2 female patients with unremarkable histories. Both of them received previous operations before visiting our center after they were diagnosed with anorectal malignant melanoma. One case underwent abdominoperineal resection and postoperative chemotherapy. The other had been treated with ultralow anterior resection followed by immunotherapy.

Synchronous Primary Anorectal Melanoma, Sigmoid Multiple Early Cancers and Descending Adenocarcinoma: A Case Report

Multiple colorectal cancers are extremely rare, few cases can be searched in the literature. Our group only found 6 cases published. We report a case where 3 diseases coexisted summarize the currently available literature. A 75-year-old man presented with changes in his bowel habits and hematochezia. After a colonoscopy with biopsies in a community hospital, he was diagnosed with a descending adenocarcinoma patient. To get further treatment, he came to our hospital. Colonoscopy revealed ulcerative lesions in the descending colon, 2 polypoid lesions in the sigmoid colon, and a protruded lesions in the anorectal. The ulcerative lesions were already diagnosed as adenocarcinoma at the descending colon. So biopsies were taken in the anorectal region, which revealed poorly differentiated melanoma of the anorectal. Computed tomography did not find distant metastases and regional lymphadenopathy. A laparoscopic resection was undertaken to relieve his symptoms and improve the quality of life. The mass showed descending adenocarcinoma, sigmoid multiple early cancers, and poorly differentiated melanoma of the anorectal region. What we can learn is that endoscopy doctors should always be aware of the possibilities of multiple primary cancers for this is important to the treatment and prognosis of patients, standard colonoscopy examination is necessary and returning a enteroscope from cecum should be more than 8 minutes.