Anorectal Melanoma Research Articles

Anorectal melanoma: systematic review of the current literature of an aggressive type of melanoma.

Anorectal melanoma (ARM) is a rare malignancy often associated with a poor prognosis due to its late diagnosis and aggressive biological behavior. This review aims to comprehensively investigate ARM's diagnosis, management, and treatment, emphasizing its clinical characteristics, laboratory findings, and implications for patient prognosis. A systematic literature search was conducted in PubMed, Embase, and Cochrane CENTRAL databases from inception to 1 July 2024. This review synthesizes existing literature to provide a comprehensive understanding of this rare primary malignancy. A total of 110 articles reporting on 166 patients were included. Gender data were available for 131 cases, comprising 67 females (51.1%) and 64 males (48.9%). The median age was 66 years. The overall median time to diagnosis was 4 months for anal melanoma, 3 months for rectal melanoma, and 4 months for anorectal junction melanoma. The clinical presentation was nodular in 98.2% of cases. Pre-diagnosis symptoms included bleeding in 84.9% of cases, mucous elimination (6%), pain (68.7%), tenesmus (16.9%), and changes in bowel movements (28.5%). Overall survival (OS) was reported in 82 cases, with a median OS of 11 months: 11 months for anal melanoma, 7 months for rectal melanoma, and 12 months for anorectal junction melanoma. ARM is a rare and aggressive melanoma subtype often diagnosed at an advanced stage, leading to a poor prognosis. A female predominance was observed, consistent with other mucosal melanomas. Anal melanoma exhibited better progression-free survival, and OS compared to rectal and anorectal junction melanoma.

Genomic landscape of cutaneous, acral, mucosal, and uveal melanoma in Japan: analysis of clinical comprehensive genomic profiling data.

Cutaneous melanoma (CM) is the most common type in Caucasians, while acral melanoma (AM) and mucosal melanoma (MM), which are resistant to immunotherapies and BRAF/MEK-targeted therapies, are more common in East Asians. Genomic profiling is essential for treating melanomas, but such data are lacking in Japan. Comprehensive genomic profiling data compiled in the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) were analyzed. A total of 380 melanomas was analyzed, including 136 CM, 46 AM, 168 MM, and 30 uveal melanoma (UM). MM included conjunctival, sinonasal, oral, esophageal, anorectal, and vulvovaginal melanomas. No significant difference in the median tumor mutational burden (TMB) of CM (3.39 mutations/megabase), AM (2.76), and MM (3.78) was the key finding. Microsatellite instability-high status was found in one case. BRAF V600E/K was found in only 45 patients (12%). Key driver mutations in CM were BRAF (38%), NRAS (21%), NF1 (8%), and KIT (10%), with frequent copy number alterations (CNAs) of CDKN2A, CDKN2B, and MYC. AM was characterized by altered KIT (30%), NRAS (26%), and NF1 (11%) and CDKN2A, CDKN2B, CDK4, MDM2, and CCND1 CNAs. MM was characterized by altered NRAS (24%), KIT (21%), and NF1 (17%) and MYC, KIT, and CDKN2A CNAs, with differences based on anatomical locations. UM bore GNAQ or GNA11 driver mutations (87%) and frequent mutations in SF3B1 or BAP1. The distinct genomic profiling in Japanese patients, including lower TMB, compared to Caucasians, is associated with poorer treatment outcomes. This result underscores the need for more effective therapeutic agents.

Challenges in Diagnosis of Melanoma from the Perspective of a Pathologist

Introduction: Melanoma is an aggressive melanocytic neoplasm with a continuously increasing incidence worldwide. Vast majority of melanoma arises from skin whereas a small subset of melanoma can arise as a primary malignancy of mucosal membranes. Gastrointestinal (GI) melanoma is usually metastatic in origin whereas primary GI melanomas are extremely rare. Anorectal Melanoma comprises of 1/% of all malignant neoplasms of this area. About 70% of these lesions are pigmented whereas 30% of them are amelanotic. Upto 25% of the patients with melanoma develops recurrent disease locally or in regional lymph nodes. Materials And Methods: This is a prospective study conducted in a tertiary care hospital comprising of six cases of Melanoma. We studied the cases according to their age, sex, clinical presentation, site, radiological findings, histopathological findings, immunohistochemical findings and treatment provided. Results: This study comprises of six cases of Melanoma among which five cases are primary one case is recurrent. Among the five primary cases, four cases have GI origin (sigmoid colon, rectum, anal canal) one case originated from skin involving left foot. There is a single case of recurrent MM involving right inguinal lymph nodes with a history of primary MM in the right lower limb. The patients belong to the age group of 6th to 8th decade with male preponderance. Histopathological examination of formalin fixed paraffin tissue sections was done followed by Hematoxylin & Eosin and Immunohistochemical staining which confirmed the diagnosis of Melanoma. Conclusion: Melanoma is an aggressive melanocytic neoplasm that carries a poor prognosis. It commonly involves skin. Its occurrence in GI tract is rare in which primary lesions are exceedingly unusual. Diagnosis and Treatment require multidisciplinary team approach with surgery remaining as a cornerstone of treatment.

Histological predictors of the unfavorable outcome of anorectal melanoma

AIM: to find histological prognostic factors for survival in patients with anorectal melanoma.PATIENTS AND METHODS: single center retrospective study of histological specimens of patients with anorectal melanoma (2005-2023). A revision of histological specimens was carried out, using the following criteria: multifocal growth, maximum tumor size, maximum thickness by Breslow, ulceration, perineural and lymphovascular invasion, as well as depth of invasion. Statistical processing was carried out using the Cox regression.RESULTS: twenty-one patients were included in the study. In all patients, treatment started with surgery: 13 (61.9%) — abdominoperineal excision (APE); 8 (28.1%) — local excision). The sample contained patients with the following initial stages of the process: IB–IIB — 12 (57.1%); III — 9 (42.9%). Nine (42.9%) patients developed local recurrence, and 8 (38.1%) — distant metastases. On univariate analysis, DFS was significantly affected by ulceration RR 0.061 (CI 95.0%; 0.004–0.097, p = 0.048), there was a trend towards the role of neurotropism RR 3.654 (CI 95.0%; 0.934–14.297, p = 0.063) and pigmentation RR 2.485 (CI 95.0%; 0.832–7.424, p = 0.103). In multivariate analysis, none of the criteria had a significant effect on DFS. On OS in univariate analysis was a trend towards an effect of Breslow invasion depth of more than 2 cm HR 1.028 (CI 95.0%; 0.998–1.060, p = 0.070) and depth of tumor invasion HR 2.117 (CI 95.0%; 0.990–4.525, p = 0.053). In multivariate analysis, none of the criteria had a significant effect on OS.CONCLUSION: evaluation of the effectiveness by histological features of skin melanoma showed the potential use of neurotropism, Breslow invasion of more than 2 cm and depth of tumor invasion as factors of unfavorable impact on DFS and OS in ARM. More trials are needed.

Anorectal Melanoma: A Case Report

Anorectal melanoma is a rare and aggressive form of mucosal melanoma that is difficult to diagnose early due to nonspecific symptoms like rectal/anal bleeding, anal pain, or the presence of an anal mass. Its prognosis is generally poor, with most cases already metastasized at diagnosis. A case report is presented of a patient initially presenting with anaemia, painful defecation and rectal bleeding, later diagnosed with stage IV anorectal melanoma. There is limited literature on this disease, leading to a lack of comprehensive understanding. Surgical resection is the main treatment, but over 80% of patients die within five years due to distant metastasis. The 5-year survival rate is estimated to be between 6% and 22%. Keywords: Anorectal, Melanoma, mucosa

Anorectal Melanoma: Not All Dark, Bleeding, and Painful Masses are Hemorrhoids

Anorectal Melanoma represents less than 1% of all gastrointestinal tumors. They are infrequent, aggressive and with little therapeutic consensus. The prognosis is usually reserved, with a five-year survival rate of less than 20%. The anorectal canal is the most common place where melanomas of the gastrointestinal mucosa appear. Thus, although it represents 0.05 to 4.6% of anorectal lesions, this constitutes the third most common location of melanoma, after the skin and eyes. Generally, their diagnosis is confusing and late, as they require a high index of suspicion; The symptoms are non-specific but they mostly present as dark, bleeding and painful masses, sometimes being confused with benign anorectal processes such as hemorrhoids. This occurred in two clinical cases that we presented in women aged 78 and 59 years with a purplish-black anorectal mass, the first case confused with hemorrhoidal thrombosis and the other with bleeding internal hemorrhoids; therefore, being treated as such in primary medical care centers and delaying their diagnosis by an average of 3 months (Figure A, B and E). Both cases with high clinical suspicion of a malignant process were later confirmed in a specialized unit, where they underwent biopsies and imaging studies. The patients underwent surgery, with subsequent chemo-immunotherapy. The first with abdomino-perineal resection (Figure C) plus inguinal lymphadenectomy (Figure E) and the other with local excision (Figure F). Both neo or adjuvant treatment and type of surgery remain controversial today.

Surgical Management of Primary Anorectal Melanoma: Is Less More?

PurposeAno-uro-genital (AUG) Mucosal Melanoma UK guidelines recommended a less radical surgical strategy for anorectal melanoma (ARM) where possible. We report our experience of ARM consistent with that approach including clinical presentation, intervention undertaken and prognosis.MethodsWe present a retrospective study of 15 consecutive patients with ARM surgically treated between November 2014 and April 2023. Patients were divided into the two surgery types: wide local excision (WLE, n = 9) and abdominoperineal resection (APR, n = 6). Data on demographics, diagnosis, treatment and oncological outcomes were assessed between the groups.ResultsThe mean age was 65.3 ± 17.4 years and 6 (40.0%) were female patients. Nine patients (60.0%) were diagnosed with stage I and six patients (40.0%) with stage II disease. R0 margins were achieved in all cases. The overall mean length of stay was lower following WLE compared to APR (2.6 ± 2.4 days versus 14.0 ± 9.8 days, p = 0.032). Two complications were observed in the WLE group compared to four complications after APR (p = 0.605). Five patients (55.5%) developed local/distant recurrence in the WLE group compared to three patients (50.0%) in the APR group (p = 0.707), with a median overall survival of 38.5 (12–83) months versus 26.5 (14–48) months, respectively.ConclusionsAchieving clear margins by the least radical fashion may have equivalent oncological outcomes to radical surgery, potentially reducing patient morbidity and preserving function. In our experience, the surgical management of ARM consistent with the ‘less is more’ approach adhering to AUG guidelines has acceptable outcomes.

Anorectal mucosal melanoma

Anorectal mucosal melanoma accounts for less than 1 % of all anorectal malignant tumors and a tendency for delayed diagnosis leads to advanced disease at presentation.1,2 Due to the rarity of the disease, there are limited prospective trials exploring the optimal treatment strategies. Generally, tumors are surgically excised, with a preference for conservative management with wide local excision. In the past decade, there have been advances with immunotherapy and other targeted therapies. Multiple clinical trials continue exploring neoadjuvant/adjuvant combination treatments in the setting of advanced or unresectable disease.

Whole-exome sequencing reveals mutational profiles of anorectal and gynecological melanoma

Mucosal melanoma is a rare and highly malignant type of melanoma. Among the sites that mucosal melanoma arises, anorectal and gynecological melanoma has more aggressive behavior and worse prognosis. There was no effective therapy for mucosal melanoma at present. Only a small number of mucosal melanoma patients which harbor mutations in BRAF or KIT benefit from targeted therapy. So it’s an urgent need to identify more actionable mutations in mucosal melanoma. To identify more potential therapeutic targets in mucosal melanoma, 48 samples were collected from 44 patients with anorectal or gynecological melanoma and subjected to whole-exome sequencing. The tumor mutation burden was low with a median of 1.75 mutations per Mb. In chromosomal level, 1q, 6p and 8q of mucosal melanoma were significantly amplified while 9p, 10p, 10q, 16p and 16q were significantly deleted. Muc16 was the most frequently mutated oncogene in our samples(25%). The mutation frequency of KIT(20%) was comparable to the "triple-wild" genes-NRAS(20%), NF1(20%), and BRAF(11%). KMT2D mutation was found in 18.18% patients, which is previously unidentified. MAPK signaling pathway and lysine degradation were the most frequently mutated pathways. Moreover, patients with TP53 mutations tend to have worse clinical outcome (median survival time 19 vs. 50 months, log-rank P = 0.006). 2000 ore mutated genes involved in MAPK signaling pathway were identified, which expand the patients potentially benefit from ample MAPK inhibitors. KMT2D could be a potential therapeutic target. Moreover, TP53 could be a potential prognosis marker for mucosal melanoma.

Bugs' eyes and black monsters: Ascitic fluid cytology in an elderly male with hematochezia.

Anorectal malignant melanomas are rare, accounting for less than 2% of all melanomas. Malignant effusions developing secondary to malignant melanoma are highly uncommon. Herein, we present the cytomorphological features of a metastatic anorectal malignant melanoma presenting with ascites at the initial clinical presentation.

Clinical and Imaging Research in the Diagnosis of Anorectal Melanoma with Surgical Outcome: A Case Report and Literature Review

Abstract Objective This study aims to report the case of a 69-year-old female patient with a diagnosis of anorectal melanoma (AM) established by immunohistochemistry. Methods Clinical case report, a descriptive and qualitative study. Results The patient had a nodular and ulcerative lesion in the anal region, the imaging exams revealed an expansive lesion that affected the rectum and the vaginal wall. The chosen course of treatment was initial surgical intervention, the surgery and postoperative course progressed without complications, and the anatomopathological examination confirmed the diagnosis of invasive malignant melanoma of the distal rectum of anorectal transition. The anatomopathological examination confirmed the diagnosis of invasive malignant melanoma located in the distal rectum of the anorectal transition. Immunohistochemistry analysis showed infiltrative melanoma with microsatellites, as well as peri and intratumoral lymphocytic infiltrate, angiolymphatic invasion, and perineural invasion. The surgical resection margins, ovaries, posterior vaginal wall, and parametrium showed no signs of neoplastic involvement. Following the surgery, the patient began immunotherapy, which she is still undergoing. Conclusions The survival rate of AM can be improved through various diagnostic and therapeutic modalities. However, further exploration of this topic through clinical studies is necessary to enhance both diagnosis and treatment.

Efficacy of immune checkpoint inhibitors in patients with anorectal melanoma in association with immune-related adverse events: a case series.

Anorectal melanoma (AM) is a rare subtype of mucosal melanoma with a poor prognosis. Given its rarity compared to its cutaneous counterpart, the benefits and side effects of immune checkpoint inhibitor (ICI) therapy and the relationship between side effects and prognosis remain unclear. Herein, we describe the clinical presentation of five patients with AM treated with ICI as well as their relationship to the treatment course and the development of immune-related adverse events (irAEs). Three patients received sequential or concurrent administrations of nivolumab and ipilimumab, one received nivolumab alone, and one received ipilimumab alone. The response rate (RR) and disease control rate (DCR) were 40% and 80%, respectively. Pituitary and hepatic dysfunctions were the most common irAEs observed (40% each), followed by thyroid, diarrhea, and renal dysfunctions (20% each). The RR was 67% in patients with irAEs while no response was observed in patients without irAEs. DCR was 100% and 50% in patients with and without irAEs, respectively. Overall survival was 34months in irAE and 8.75months in non-irAE cases, with a longer survival trend in irAE cases. ICI therapy was effective and well-tolerated by AM patients, with potentially better outcomes for those who experienced irAEs compared to those who did not.

Breast metastasis as the first presentation of an anorectal melanoma diagnosed on fine needle aspiration cytology: a case report

BackgroundPrimary anorectal melanoma is a rare and aggressive disease accounting for approximately 1–3% of all colorectal and anal cancers.Case reportWe present a unique case of anorectal melanoma where the primary presentation was the metastatic breast lump which led to the detection of the primary tumor. A 70-year-old elderly postmenopausal female presented with complaint of left breast lump. On fine needle aspiration cytology, May Grunwald-Giemsa and Papanicolaou stained smears examined were highly cellular and showed sheets, clusters and singly scattered highly pleomorphic plasmacytoid cells having high nucleus to cytoplasmic ratio and scant to moderate cytoplasm with enlarged eccentric round to ovoid nuclei. Immunocytochemistry performed on cell block preparation showed tumor cells strongly positive for HMB-45, S-100 and negative for ER, PR, Her2neu, chromogranin, synaptophysin and Pan-CK. A thorough work up of the patient to look for the site of primary malignancy was done and radiological findings reveled presence of an ill-defined soft tissue mass in the anal canal. Biopsy from the anal mass confirmed the diagnosis of anal melanoma with metastasis to breast.ConclusionThe present case was reported to emphasize the importance of atypical presentation where the breast lump was the primary presentation of an anal melanoma. Therefore, we should have a strong index of suspicion for metastatic tumors in case of a breast lump especially when there is unusual morphology or unexpected immunophenotype, particularly if the neoplasm is triple-negative, in patients with a previous history of other malignancies.

Anorectal melanoma.

Anorectal melanoma is an aggressive mucosal melanoma subtype with a poor prognosis. Although recent advancements have been seen for cutaneous melanoma, the optimal treatment paradigm for management of anorectal melanoma is evolving. In this review, we highlight differences in the pathogenesis of mucosal versus cutaneous melanoma, new concepts of staging for mucosal melanoma, updates to surgical management of anorectal melanoma, and current data for adjuvant radiation and systemic therapy in this unique patient population.

Epidemiology and outcomes of anorectal melanomas: A national database analysis.

e21572 Background: Anorectal melanoma is a rare but aggressive type of melanoma, arising primarily from the mucosal epithelium from the anorectal tract. Knowledge of this rare etiology has been limited given its low incidence. This study aims to characterize the epidemiology and treatment outcomes of anorectal melanoma using a national database. Methods: The Surveillance, Epidemiology and End Results (SEER) Database was queried to identify patients with biopsy-proven anorectal melanoma. The following information was retrieved: tumor site, grade, stage, intervention, lymph node histology, and survival information for oncology codes as per the international classification of diseases. Statistical analysis was performed with Stata 15.1 (STATA Corp., College Station, TX, USA). Results: The age-adjusted anorectal melanoma annual incidence rates have been stable approximately 0.4-0.5 per 1 million from 2000 to 2019. Of the 823 biopsy-proven confirmed cases of anorectal melanoma from 2000 to 2018, 150 (18.2%) received chemotherapy, 182 (22.1%) received radiotherapy, 55 (6.7%) received chemoradiation, while 619 (75.2%) of the population received surgery alone or combined with chemotherapy and/or radiotherapy. Statistically significant improvement in survival was noted in treatment strategies that utilized surgery with and without chemotherapy and/or radiotherapy (median survival time 22 vs 9 months, p < 0.0001). Patients with positive regional lymph nodes on pathology were associated with worse prognosis (median survival time 15 vs 37 months, p < 0.0001). Outcomes did not differ based on sex (p = 0.810) and race (p = 0.372). Conclusions: Incidence of anorectal melanoma in the United States has been stable in the last twenty years. Treatment strategies including surgical resection should be adopted if possible to achieve improved survival outcomes.

Clinical Review of Mucosal Melanoma: The 11-Year Experience of a Referral Center.

Mucosal melanoma is a rare neoplasm. Late diagnosis is caused by occult anatomic sites and scarcity of symptoms. Novel biological therapies have now become available. Demographic, therapeutical and survival records on mucosal melanoma are scarce. To provide an 11-year retrospective clinical review of real-world data on mucosal melanomas managed in a tertiary referral center in Italy. We included patients with histopathological mucosal melanoma diagnoses from January 2011 to December 2021. Data were collected until the last known follow-up or death. Survival analysis was performed. Among 33 patients, we found 9 sinonasal, 13 anorectal and 11 urogenital mucosal melanomas (median age 82, females 66.7%). Eighteen cases (54.5%) presented with metastasis (p<0.05). In the urogenital subgroup, only 4 patients (36.4%) had metastasis at diagnosis, all in regional lymph nodes. Sinonasal melanomas were surgically managed with a debulking procedure (44.4%); every case of anorectal and urogenital melanomas underwent radical surgery (30.8% and 45.5%). Fifteen patients were treated with biological therapy (p<0.05). Radiation therapy was used in all melanomas of the sinonasal region (p<0.05). Overall survival was longer for urogenital melanomas (26 months). Univariate analysis showed an increased hazard ratio for death in patients with metastasis. A negative prognostic value of metastatic status was reported by the multivariate model, while administration of first-line immunotherapy demonstrated a protective role. At diagnosis, the absence of metastatic disease is the most relevant factor that influences the survival of mucosal melanomas. Moreover, the use of immunotherapy might prolong the survival of metastatic mucosal melanoma patients.

Malignant Melanoma of the Anorectal Region: A Case Study and Review of the Contemporary Treatment Options

Aims: Anorectal melanoma, an uncommon malignancy of mucosal origin accounts for 0.05 per cent of all colorectal malignancies and 1 per cent of tumours of the anal canal. The typical clinical presentation includes local pain, palpable mass, bleeding, change in bowel habits, and weight loss. The symptoms are somewhat nondescript and unremarkable and can be easily confused with other conditions native to the region. Hence, a careful and timely assessment is imperative in treating this condition.&#x0D; Presentation of Case: A case involving a 54-year-old male who presented with a 3-month history of rectal bleeding and pain. Further assessment revealed a malignant melanoma of the anal canal. After undergoing laparoscopic abdominoperineal resection, the patient was on 6 cycles of dacarbazine. He was subsequently found to have liver metastasis. He subsequently started oral Temozolomide for 2 cycles. He has been on close follow-up for the last 6 months and the disease has not progressed since.&#x0D; Discussion: The course of evaluation in suspected cases of anorectal melanoma is a rectal examination, biopsy and histopathologic examination. Immunohistochemistry aids in the confirmation of the diagnosis. Laparoscopic abdominoperineal resection demonstrates good response rates. Adjuvant chemotherapy in anorectal melanoma can be given in patients following surgical resection of the primary anorectal tumour and with a high risk of recurrence. Targeted therapies like c-kit inhibitors, BRAF inhibitors, anti- CTLA-4 antibodies and anti-PD-1 antibodies can also be used.&#x0D; Conclusion: Melanomas of the anorectal region present a diagnostic dilemma and carry poor prognoses. Despite an aggressive management approach, the disease maintains an average five-year survival rate of 20%.

Malignant Melanoma of Anorectum: A Report of Five Cases

BACKGROUND: Anorectal melanoma (ARM) is an extremely rare, highly aggressive form of a tumor with the worst prognosis. ARM contributes 0.5% of all melanoma cases. Its presentation is similar to that of adenocarcinoma of the rectum, hemorrhoids, or solitary rectal ulcer, the incorrect clinical diagnosis or delayed diagnosis is often made. The definite diagnosis is only made through histopathology in which immunohistochemical stains positive to S-100, Melan A, and HMB-45 which differentiates it from adenocarcinoma of the rectum. Because of the limited number of patients and retrospective design of studies to date, there is no proven efficacy of abdominoperineal resection (APR) over local excision (LE) in terms of survival. Furthermore, this neoplasm is quite resistant to chemoradiotherapy. It has a median survival of 18 months and a 5-year survival rate of only 6%. PRESENTATION OF OUR CASES: Here, we report 5 rare cases of anorectal malignant melanoma presented to our institute between 2018 to 2022, who were treated with APR and diversion colostomy. The first case is a 27-years old young female with typical complaints, she was diagnosed ARM with locoregional metastasis. Only a diversion colostomy was performed and referred to an oncologist for palliation. Our second case is a 68-years old male with a similar complaint who presented relatively early and was diagnosed with localized disease. Conventional APR was performed and referred for adjuvant chemoradiotherapy, but the patient refused. However, the lump recurred after 6 months of tumor excision. The third case is a 29 years old male again early presentation with a similar complaint labeled as localized diseased. The conventional APR was performed followed by adjuvant chemoradiation; patient presented with metastatic disease after 6 months. The fourth case is a 60-years old male with typical history and diagnosed with localized disease. Conventional Extra-levator APR was performed followed by adjuvant therapy, but patient developed recurrence of disease with mets after 4 months. The fifth case is a 39-years old female diagnosed as ARM, had advance disease and metastatic deposits at the time of presentation, refused any palliative treatment. The study aims to evaluate our experience in treating this neoplasm. CONCLUSION: Because of the rarity of this neoplasm, no proper trial has been conducted so far. The role of chemoradiotherapy is questionable and the surgical approach varies from radical APR to conservative LE. No surgical approach has been standardized in terms of survival.

Malignant melanoma of the anal canal: A rare case report from a tertiary care center in South India

Anorectal melanoma is a rare entity that accounts for less than 1% of all anorectal malignancies. It is often mistaken for benign anorectal conditions since the symptoms resemble each other. The predominant symptoms of anorectal melanoma are per rectal bleeding, anorectal pain, mass per rectum, tenesmus and altered bowel habits. All suspected cases of anorectal malignancy should be subjected to sigmoido-colonoscopy and biopsy. Management of anorectal melanoma remains controversial including surgery, chemotherapy, radiotherapy and target therapy as treatment options. Surgical treatment is considered as the primary treatment modality for anorectal melanoma. Anorectal melanoma must be kept in mind as differential diagnosis for patients presenting with per rectal bleeding and pain.

The optimal surgical volume for anorectal melanoma: a retrospective analysis of the Russian Colorectal Cancer Society registry

Background . Anorectal melanoma is a rare malignancy without established standard treatment. Aim . To analyse the Russian Colorectal Cancer Society melanoma registry and to assess optimal surgery with regard to the extent of the disease. Materials and methods . A retrospective analysis of the Russian Colorectal Cancer Society registry was carried out during 2000–2020. Patients with cutaneous melanoma colonic metastases as well as patients with less than 6 months follow-up were excluded. Basic patient group characteristics, overall and disease-free survival (were analyzed depending on disease stage (by A. Stefanou) and surgery type. Results . 16 patients had stage I–IIA, 24 – stage IIB, 29 patients – stage III and 24 patients – stage IV disease. Wide local excision was performed in 15 (93.8 %) patients with stage I–IIA, 15 (62.5 %) patients with stage IIB, 2 (6.9 %) patients with stage III, and 8 (33.3 %) patients with stage IV disease. Abdomino-perineal excision (APE) was performed in 0 patients with stage I–IIA, 7 (29.2 %) patients with stage IIB, 22 (75.9 %) patients with stage III, and 7 (29.2 %) patients with stage IV disease. 2-year overall survival was 74.5 % in stage I–IIA, 49.4 % in stage IIB, 64.3 % in stage III, and 10.4 % in stage IV disease; 2-year disease-free survival was 67 %, 23,4 %, 34,1 % in stage I–IIA, IIB, III disease accordingly. Median overall survival was 17.8 months, 38.3 months and 27.9 months for non-surgical treatment, wide local excision and APR in non-metastatic patients accordingly. Median disease-free survival was 6.0 months, 14.1 months and 12.0 months for non-surgical treatment, wide local excision and APR in non-metastatic patients accordingly. Conclusions . APR should be considered in patients with stage IIB and stage III (by A. Stefanou) anorectal melanoma. Wide local excision is the preferred treatment in other patients.