Selected abstracts on Anal Malignant melanoma.

1: Tech Coloproctol. 2005 Apr;9(1):60-2.

Anal melanoma in the era of sentinel lymph node mapping: a diagnostic and therapeutic challenge.

Olsha O, Mintz A, Gimon Z, Gold Deutch R, Rabin I, Halevy A, Reissman P.

Department of Surgery, Shaare Zedek Medical Center , Ben-Gurion University , Jerusalem 91031 , Israel .

Melanoma of the anal canal is a rare malignancy that often has an atypical presentation. Locoregional metastases, which are often present at the initial presentation, may occur in both groin and pelvic lymph nodes, but the utility of lymph node dissection remains unknown. We explored the possibility of applying the technique of sentinel lymph node (SLN) mapping to anal melanoma. SLN mapping was performed in 2 patients with anal melanoma. Radioactive tracer and blue dye were injected around the lesions. The SLN was identified pre-operatively by lymphoscintigraphy, and at surgery with a hand-held gamma detector and by visualization of the dye. The SLN was identified in both patients, only in the groin in one and only in the presacral region in the other. One patient had a wide local excision of the anal lesion with house flap anoplasty, while the other had abdominoperineal resection with total mesorectal excision. There were no SLN metastases in either patient. The technique of SLN mapping and biopsy is easily adapted to surgery for malignant melanoma of the anus. SLN mapping and biopsy could aid in planning surgical strategy, but definitive conclusions may only be reached after more experience has been acquired.

2: Pathologe. 2004 May;25(3):171-7.

[Anorectal melanoma. A rare and highly malignant tumor entity of the anal canal]

Helmke BM, Otto HF.

Pathologisches Institut, Universitat Heidelberg.

Burkhard-Helmke@med.uni-heidelberg.de

Anorectal melanomas represent a very small group of mucosal melanoma with unknown etiology and poor prognosis. In view of their location, a history of sun exposure is not likely to have had an impact on their development. Recent epidemiologic data indicate a bimodal age distribution. To date there is no information whether an infection with the human papilloma virus plays a role in the tumorigenesis of anorectal melanoma. The lesions can be misdiagnosed as hemorrhoids on clinical examination. On histological examination amelanotic types have been misdiagnosed as lymphoma, sarcoma,and undifferentiated carcinoma. Useful immunohistochemical markers are S 100 protein, HMB-45, Melan A, and MiTF (microphthalmia-transcription-factor). Therapy includes local excision or abdominoperineal resection followed by optional inguinal and parailiac lymph node dissection, and consecutive chemo- and immunotherapy. The poor long-term prognosis of anorectal melanomas correlates with their advanced tumor size and depth of infiltration at diagnosis. The overall 5-year survival rates range between <5 and 22% in different series.

3: Surg Oncol Clin N Am. 2004 Apr;13(2):249-62.

Overview of anal cancer for the surgeon.

Rousseau DL Jr, Petrelli NJ , Kahlenberg MS.

Division of Surgical Oncology, Department of Surgery, University of Texas Health Science Center , 7703 Floyd Curl Drive , Mail Code 7738, San Antonio , TX

78229-3900, USA . rousseaud@uthscsa.edu

Cancers of the anal canal represent a diverse group of pathology and require a multidisciplinary approach for treatment. For the most common anal canal cancer, anal SCC, the primary therapy is CMT with systemic chemotherapy and radiation. The surgeon plays a key role in the diagnosis and follow-up after treatment, with surgical intervention reserved for residual or recurrent disease. The overall prognosis for this disease is favorable. For anal adenocarcinoma, aggressive surgical resection remains the mainstay of therapy, with radiation therapy and chemotherapy used to aid in local disease control and for treatment of metastatic disease. A high rate of distant failure in this disease is responsible for the poor long-term prognosis. Anorectal melanoma has a high rate of distant failure and a poor overall survival rate. Surgical intervention is focused on local disease control with preservation of sphincter function. The biggest improvements in survival for this disease will come with more effective systemic therapy.

4: J Cutan Pathol. 2000 May;27(5):215-7.

Histopathological features of flexural melanocytic nevi: a study of 40 cases.

Rongioletti F, Ball RA, Marcus R, Barnhill RL.

Centre of Dermatopathology, Institute of Dermatology , University of Genoa , Italy . lonetti@unige.it

Melanocytic nevi in certain locations such as the genital and acral sites may have atypical histologic features simulating melanoma. We studied the microscopic findings of 40 melanocytic nevi of flexural sites (axilla, umbilicus, inguinal creases, pubis, scrotum and perianal area) to verify if flexural nevi show distinctive features similar to melanocytic nevi of the genital skin. The patients were young (mean age 20 years), the lesions were mostly removed for cosmetic reasons and we are not aware of any deaths or complications related to the removed nevi. We found that 22 (55.5%) out of 40 flexural nevi had "a nested and dyshesive pattern" similar to the melanocytic nevi of genital skin. This pattern was characterized by the confluence of enlarged nests with variation in size, shape and position at the dermo-epidermal junction and by the diminished cohesion of melanocytes. Dermatopathologists should pay attention to the "nested and dyshesive pattern" of flexural nevi that may mimick histologic changes of melanoma.

5: Surg Today. 1999;29(2):170-3.

Primary anorectal malignant melanoma: report of a case.

Ojima Y, Nakatsuka H, Haneji H, Kurihara T, Sadamoto S, Ohmoto T, Katayama N, Taniyama K. Department of Surgery, Kure City Medical Association Hospital , Hiroshima , Japan .

Primary anorectal malignant melanoma is a fairly uncommon but highly malignant disease. This disease is sometimes mistaken for such benign conditions as either a hemorrhoid or rectal polyp. We herein describe a case of early primary malignant melanoma of the anal canal. In this case, magnetic resonance (MR) imaging was found to be useful for diagnosing the melanotic melanoma. We especially emphasize the usefulness of a fat-saturation MR image in distinguishing melanotic melanoma from other rectal tumors.

6: Bull Cancer. 1997 Apr;84(4):423-6.

[Malignant anorectal melanoma: description of a clinical case and review of the literature]

Malaguarnera M, Pistone G, Succi L, Pontillo T, Laurino A, Russello D.

Departement de medecine interne et de geriatrie, Universite des etudes de Catania , Italie.

Malignant ano-rectal melanoma is a rare pathology without characteristic symptoms. It is more frequent in females than in males (ratio 2:1) and represents 3-15% of anal canal tumours. A case of a woman who recently came to us complaining of painful defecation, tenesmus and rectal bleeding induced us toreconsider the diagnostic and therapeutic implications in ano-rectal melanoma. The low incidence of cases reported and the negative 5-year prognosis are due to late, often incidental, diagnosis during clinical observation for hemorrhoids, rectal polyps or rhagades, together with the aspecificity of the tumour symptoms. We hope our case report emphasizes the importance of conducting early diagnosis in patients at risk of ano-rectal melanoma.