The clinical features and optimal treatment of anorectal malignant melanoma

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.

Anorectal and Genital Mucosal Melanoma: Diagnostic Challenges, Current Knowledge and Therapeutic Opportunities of Rare Melanomas

Mucosal melanomas (MM) are rare tumors, being less than 2% of all diagnosed melanomas, comprising a variegated group of malignancies arising from melanocytes in virtually all mucosal epithelia, even if more frequently found in oral and sino-nasal cavities, ano-rectum and female genitalia (vulva and vagina). To date, there is no consensus about the optimal management strategy of MM. Furthermore, the clinical rationale of molecular tumor characterization regarding BRAF, KIT or NRAS, as well as the therapeutic value of immunotherapy, chemotherapy and targeted therapy, has not yet been deeply explored and clearly established in MM. In this overview, focused on anorectal and genital MM as models of rare melanomas deserving of a multidisciplinary approach, we highlight the need of referring these patients to centers with experts in melanoma, anorectal and uro-genital cancers treatments. Taking into account the rarity, the poor outcomes and the lack of effective treatment options for MM, tailored research needs to be promptly promoted.

Difficulties in diagnosing anorectal melanoma: A case report and review of the literature

BACKGROUND

Anorectal melanoma is a tumour that is difficult to identify due to its rarity and variability of presentation. Insufficient data published in the literature do not allow for diagnostic and treatment guidelines to be established. Anorectal melanoma has the worst prognosis among mucosal melanomas and is frequently misdiagnosed by standard identification methods.

CASE SUMMARY

A 66-year-old woman presented with intermittent anal bleeding, pain, and tenesmus in the past month, with no associated weight loss. Colonoscopy revealed a cauliflower-like tumour with a diameter of 1.5 cm, with exulcerated areas and an adherent clot but without obstruction. Biopsy results identified an inflammatory rectal polyp with nonspecific chronic rectitis. Tumour markers CA 19-9 and CEA were within the normal range. After 6 mo, due to the persistence of symptoms, a pelvic magnetic resonance imaging scan was performed. A lesion measuring 2.8 cm × 2.7 cm × 2.1 cm was identified at the anorectal junction, along with two adjacent lymphadenopathies. No distant metastases were detected. Immunohistochemistry was performed on the second set of biopsies, and a diagnosis of anorectal melanoma was established. Surgical treatment by abdominoperineal resection was performed. Evolution was marked by the appearance of lung metastases at 1 mo postoperatively, detected on a positron emission tomography-computer tomography scan, and perineal recurrence after 5 mo. After molecular testing, the patient was included in an immunotherapy trial.

CONCLUSION

This case highlights the difficulty of establishing a definitive early diagnosis of anorectal melanoma, the importance of performing histological analysis on a well-represented biopsy specimen, and the poor prognosis, even with radical surgery.

Anorectal Melanoma Misdiagnosed as Hemorrhoids: A Case Report and Review of the Literature

Anorectal melanoma is a rare and aggressive malignant neoplasm with an indolent course, manifesting with nonspecific symptoms and a poor prognosis. We present a case of anorectal melanoma that was initially treated as hemorrhoids and correctly diagnosed after lower gastrointestinal endoscopy. We also present the latest findings in the literature about anorectal melanomas and discuss updates about treatment options and management.

Distribution pattern of tumor infiltrating lymphocytes and tumor microenvironment composition as prognostic indicators in anorectal malignant melanoma

Anorectal malignant melanoma (ARMM) is a rare disease with poor prognosis. Determining ARMM prognosis precisely is difficult due to the lack of proper assessment techniques. Immunotherapy has proven effective against cutaneous malignant melanoma and may show efficacy in ARMM. Herein, we assessed the immune profile of ARMM to identify possible prognostic biomarkers. Twenty-two ARMM formalin-fixed and paraffin-embedded samples were evaluated using an nCounter^® PanCancer Immune Profiling Panel. Validation was performed through immunohistochemical staining for CD3, CD8, Foxp3, CD68, CD163, and PD-L1. RNA analysis revealed significantly decreased scores for pathways involved in cell regulation and function, as well as chemokines, in recurrent patients compared to nonrecurrent patients. In cell-type profiling, the recurrent cases displayed significantly low tumor infiltrating lymphocyte (TIL) scores. Recurrence/death prediction models were defined using logistic regression and showed significantly lower scores in recurrent and deceased patients (all, P < 0.001) compared to those in nonrecurrent and surviving patients. The high total TIL and tumor-associated macrophage (TAM) groups had significantly better overall survival outcomes compared to the low total TIL and TAM groups (P = 0.007 and P = 0.035, respectively). In addition, the presence of CD3 + TILs in the invasion front was an independent favorable prognostic indicator (P = 0.003, hazard ratio = 0.21, 95% confidential interval, 0.01-0.41). Patients with inflamed or brisk-infiltration type tumors also had a significantly better overall survival than that of patients with immune-desert/excluded and absent/non-brisk type tumors (P = 0.03 and P = 0.0023, respectively). In conclusion, TILs have a strong prognostic value in ARMM, and the quantification of TILs and an analysis of the TIL phenotype and infiltration pattern during pathological diagnosis are essential to guide treatment strategies and accurate prognosis in ARMM.

Presentation, Management, and Prognosis of Primary Gastrointestinal Melanoma: A Population-Based Study

BACKGROUND

Primary gastrointestinal (GI) melanomas, compared with cutaneous melanomas, have a much lower incidence. As a result, there is a paucity of data regarding their presentation, treatment, and prognosis. The aim of this study was to analyze the incidence, patient characteristics, treatment patterns, and survival of primary GI melanomas in comparison with cutaneous melanomas using a population-based cohort.

METHODS

Patients diagnosed with primary GI and cutaneous melanomas were identified from Surveillance, Epidemiology, and End Results 1973-2016 data.

RESULTS

A total of 872 primary GI melanomas and 319,327 cutaneous melanomas were identified. GI melanoma incidence increased by an annual percent change of 1.82 (P < 0.05) during the study period. The most common sites for GI melanoma were the anus (50%) and rectum (34%). Compared to cutaneous melanoma, patients diagnosed with GI melanomas were older, women (58% versus 45%), non-White (16% versus 6%), and presented with a higher stage (36% versus 4% distant stage, all P < 0.001). GI melanomas had significantly worse cancer-specific survival (CSS) than cutaneous melanoma. Despite the poor prognosis, the CSS has increased in recent years. Among patients with anorectal melanomas, local excision with chemotherapy and/or radiation had a similar CSS compared with those with major surgery only.

CONCLUSIONS

Despite a steady increasing incidence since 1975, GI melanomas are rare, present with advanced stages, and have worse outcomes than cutaneous melanomas. The improved prognosis of these tumors in recent years might reflect the impact of novel targeted treatments and the more common use of local tumor excision over major resections.

A case report of anorectal malignant melanoma in the transitional zone

INTRODUCTION

Anorectal malignant melanoma is an uncommon and highly malignant disease with a greater incidence in females. Many patients were misdiagnosed as hemorrhoids, benign polyps, and rectal cancer. They were often diagnosed in an advanced stage. Wide local excision and abdominoperineal resection are the main treatments of rectal melanoma.

PRESENTATION OF CASE

A case report is a 77-year-old man who has blood in the stool for 4 months without clinical examination. He admitted to the emergency room with sudden syndromes that related to bowel perforation. Rectal examination detected a large anorectal polyp. Computer tomography showed free air and fluid in the peritoneal cavity. He was received laparoscopic surgery and found the fishbone penetrated the sigmoid colon without polyp resection. The polyp was treated by local excision a few days later. The histology examination was a primary malignant melanoma. Due to the pigmented lesion that remained from the resected polyp's root, the abdominoperineal resection was performed as a radical treatment.

DISCUSSION

Diagnosis of anorectal malignant melanoma is difficult because of atypical signs, that are confused with bleeding hemorrhoids especially an amelanotic melanoma. Treatment is controversial, including surgery, radiotherapy, chemotherapy, and target therapy. A present case is an option in radical surgery.

CONCLUSION

Anorectal melanoma is a rare disease with poor results and prognosis. A lack of large-data leads to a missing evidence-based guideline in this disease. Early-staging diagnosis and surgical treatment help patients improve their overall survival.

Primary anorectal malignant melanoma: A case report

INTRODUCTION

Anorectal malignant melanoma (AMM) is a rare and aggressive malignance with poor prognosis, yet no consensus of treatment exists to date. Abdominoperineal resection surgery (APR) is the standard treatment of anorectal malignant melanoma, capable of controlling lymphatic spread and obtaining a large negative margin for local control but it can lead to complications. Wide local excision (WLE) allows for quicker recovery and has minimal impact on bowel function (i.e., bypassing the need for a stoma).

PATIENT CONCERNS

A 66-year-old male patient presented with a 2-months history of painless rectal bleeding.

DIAGNOSIS

The characteristic finding from colonoscopy and magnetic resonance imaging led to a diagnosis of colorectal cancer. Immunohistochemistry analyses confirmed malignant melanoma. The tumor was classified as: HMB-45(+), S-100(+), CD117(±), PCK(-), ki-67(+, 10%).

INTERVENTIONS

The patient underwent abdominoperineal resection with no other adjuvant therapy.

OUTCOMES

The patient is doing well at 24 month after the operation, with no signs of recurrence.

CONCLUSION

AMM is a rare malignance, and is easy to misdiagnose. The therapy approach remains controversial. Every effort should be made to ensure prompt diagnosis and to define the optimally effective standard therapy approach.

Endoscopic submucosal dissection as excisional biopsy for anorectal malignant melanoma: A case report

BACKGROUND

Anorectal malignant melanoma (AMM) is a rare disorder with an extremely poor prognosis. Although there is currently no consensus on the treatment methods for AMM, surgical procedures have been the most common treatment methods used until now. We recently encountered a case of AMM that we diagnosed using endoscopic submucosal dissection (ESD). To our knowledge, this is the first case of ESD for AMM, suggesting that ESD can potentially be a diagnostic and treatment method for AMM.

CASE SUMMARY

A 77-year-old woman visited our hospital with a chief complaint of anal bleeding and a palpable rectal mass. Colonoscopy revealed a 20-mm protruded lesion in the lower rectum. After obtaining biopsy specimens from the lesion, although a malignant rectal tumor was suspected, a definitive diagnosis was not made. Endoscopic ultrasonography revealed tumor invasion into the submucosal layer but not the muscular layer. Therefore, we performed an excisional biopsy using ESD. Immunohistochemical examination of the ESD-resected specimen revealed tumor cells positive for Human Melanin Black-45, Melan-A, and S-100. Moreover, the tumor cells lacked melanin pigment; thus, a diagnosis of amelanotic AMM was made. Although the AMM had massively invaded the submucosal layer and both lymphatic and venous invasion were present, we closely monitored the patient without any additional therapy on the basis of her request. Six months after ESD, local recurrence was detected, and the patient consented to wide local excision.

CONCLUSION

It is suggested that ESD is a potential diagnostic and treatment method for AMM.

Patterns of Care and Survival Outcomes in the Treatment of Anal Melanoma

PURPOSE

Anal mucosal melanoma is an uncommon malignancy of the anal canal, with few large studies available to establish clear trends in the treatment modalities presently available. The primary goal of this study was to identify the patterns of care in the treatment of anal melanoma and secondarily to determine outcomes.

METHODS

This was a retrospective study performed utilizing the National Cancer Database (NCDB). A total of 787 patients diagnosed with anal melanoma between 2004 and 2014 were selected, of which 398 had staging information. The four treatment groups analyzed were surgical excision alone, surgical excision and radiation therapy, surgical excision and immunotherapy/chemotherapy, and radiation therapy plus minus immunotherapy/chemotherapy. Treatment was grouped by extent of disease; the Kaplan-Meier method was used to analyze overall survival and multivariate Cox proportional model was used to identify factors associated with overall survival.

RESULTS

The majority of patients presented with either node-positive (39.4%) or metastatic disease (37.4%). Patients with surgical excision and radiation therapy had the highest median survival at 32.3 months. This is in contrast with those receiving surgical excision alone (22.9 months), surgery and immunotherapy/chemotherapy (18.4 months), and radiation without surgery (5.1 months) (p < 0.0001).

CONCLUSIONS

Treatment with surgical excision was the most common initial treatment with no single modality superior over another in this rare entity.

Amelanocytic anorectal malignant melanoma-Case report

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Anorectal malignant melanoma, is a rare and aggressive form of melanoma.

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Very different from its cutaneous counterpart.

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There is no optimal treatment. Surgery is the mainstay of treatment, but the extent is controversial.

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Patient’s quality of life deserves attention when choosing the adequate surgical technic.

Introduction

Anorectal malignant melanoma (AMM), is a rare and aggressive form of melanoma. Accounts for <2% of melanomas, and <2% of anal tumors. It is more frequent at the 6^th–7^th decade, mostly in women. Surgery is the mainstay of treatment, but the extent is controversial.

Case presentation

82-year-old male, presented with rectal mass in the Emergency Room (ER). After local excision, pathology observed that the mass corresponded to AMM. Despite being stage I (Local disease), a year later it presented with local recurrence and distant metastasis. The patient died 32 months after diagnosis.

Conclusions

There is no optimal treatment, due to the lack of prospective studies. Wide local excision (WLE) has faster recovery, less post-operatory complications and similar survival rate compared to abdominal perineal resection (APR).

Notch1 signaling in melanoma cells promoted tumor-induced immunosuppression via upregulation of TGF-β1

Background

The receptors of Notch family play an important role in controlling the development, differentiation, and function of multiple cell types. The aim of this study is to investigate the role of Notch1 signaling upon immune suppression induced by melanoma cells.

Methods

Melanoma cell line B16 cells were transfected by lentivirus containing mouse Notch1 gene or Notch1 shRNA to generate B16 cell line that highly or lowly expressed Notch1. Notch1 in anti-tumor immune response was comprehensively appraised in murine B16 melanoma tumor model in immunocompetent and immunodeficient mice. The ratios of CD3⁺CD8⁺ cytotoxic T cells, CD49b⁺NK cells, CD4⁺CD25⁺FoxP3⁺ Tregs and Gr1⁺CD11b⁺ MDSCs in tumor-DLN or spleen were examined by flow cytometry. After the co-culture of B16 cells and CD8⁺ T cells, the effects of Notch1 on the proliferation and activation of T cells were assessed by CCK8 assay, CFSE dilution and Chromium-release test. The mRNA expression and supernatant secretion of immunosuppressive cytokines, TGF-β1, VEGF, IL-10 and IFN-γ were measured by RT-PCR and ELISA, respectively.

Results

Downregulation or overexpression of Notch1 in B16 melanoma cells inhibited or promoted tumor growth in immunocompetent mice, respectively. Notch1 expression in B16 melanoma cells inhibited the infiltration of CD8+ cytotoxic T lymphocytes and NK cells and reduced IFN-γ release in tumor tissue. It could also enhance B16 cell-mediated inhibition of T cell proliferation and activation, and upregulate PD-1 expression on CD4⁺ and CD8⁺ T cells. The percentage of CD4⁺CD25⁺FoxP3⁺ Tregs and Gr1⁺CD11b⁺MDSCs were significantly increased in tumor microenvironment, and all these were attributed to the upregulation of TGF-β1.

Conclusion

These findings suggested that Notch1 signaling in B16 melanoma cells might inhibit antitumor immunity by upregulation of TGF-β1.

Transanal Endoscopic Microsurgery for Patients with Rare Rectal Tumors

BACKGROUND

Transanal endoscopic microsurgery (TEM) has been accepted worldwide for the treatment of local rectal lesions. Rare rectal tumors consist of several different types of malignant or benign tumors. Surgical management is considered to be the only curative option. The aim of this study is to investigate the role of TEM in the treatment of rare rectal tumors.

MATERIALS AND METHODS

A total of 147 patients with rare rectal tumors underwent TEM in our center from April 2006 to May 2017. Clinical data were collected and a retrospective accurate database was constructed. Demographic characteristics, operative details, tumor details, complications, and follow-up data were analyzed.

RESULTS

Seventy-eight patients were male. Mean tumor diameter was 1.2 ± 0.7 cm and mean distance from the anal verge was 6.6 ± 2.3 cm. Full-thickness and complete resection with negative margins was achieved in all patients. Complications occurred in 3 patients during surgery and in 20 patients after surgery. Histopathologic results were neuroendocrine tumors in 104 patients; gastrointestinal stromal tumors in 35; melanoma, lymphoma, and leiomyoma each in 2; lipoma, and squamous carcinoma each in 1. One hundred thirty-five patients were followed up for 49.3 ± 33.2 months. Two patients died, 1 had local recurrence and 1 had a rectovaginal fistula 1 month after surgery. No local recurrence or metastasis, or fecal incontinence was observed in the remaining patients.

CONCLUSION

TEM is an optimal treatment option for selected rare rectal tumors. The complication rate is low and the therapeutic effect is satisfactory.

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.

Assessment of Melanocyte Density in Anorectal Mucosa for the Evaluation of Surgical Margins in Primary Anorectal Melanoma

OBJECTIVES

Accurate histopathologic evaluation of surgical resection margins for anorectal melanoma (AM) is diagnostically challenging but essential to clinical management. We studied intraepithelial melanocyte density and growth pattern in anorectal mucosa and BRAF V600E mutation status in AM compared to controls.

METHODS

Histomorphology and melanocytic immunostains, microphthalmia transcription factor (MITF) and human melanoma black 45 (HMB45), were evaluated. Utility of VE1 immunostaining for determination of BRAF V600E mutation status was studied.

RESULTS

Immunostains aid in the distinction between "trailing" melanoma in situ (MIS) and benign melanocyte hyperplasia (BMH), by facilitating assessment of melanocyte density, and evaluation of nuclear atypia and growth pattern. While respective melanocyte densities overlapped, "trailing" MIS could be distinguished by melanocyte nuclear atypia and near confluent growth, compared to the banal cytology and scattered growth of BMH.

CONCLUSIONS

In the histopathologic assessment of AM resections, MITF and HMB45 immunostains aid in distinguishing between "trailing" MIS and BMH, by highlighting melanocyte density, nuclear atypia, and growth pattern, with the latter two being reliable features. VE1 showed nonspecific immunopositivity in anorectal glandular epithelium, a potential diagnostic pitfall when assessing BRAF mutation status.

Perianal melanoma with a BRAF gene mutation in a young Portuguese Roma native

A case of a young man diagnosed with perianal nodular melanoma with a gene mutation, accompanied by regional and pulmonary metastases on initial presentation, and later on with hepatic and bone involvement, is presented. The patient underwent wide local excision but was unresponsive to dacarbazine. Targeted therapy with vemurafenib had shown clinical improvement for a 5-month duration until he showed signs of disease progression. Just after the shift of adjuvant therapy to ipilimumab, he was diagnosed with multiple cerebral metastases that eventually led to his demise 6 months after initiation of vemurafenib, having had a 12-month survival period from the time of initial melanoma diagnosis.

Incidence, Surgical Treatment, and Prognosis of Anorectal Melanoma From 1973 to 2011: A Population-Based SEER Analysis

Anorectal melanoma (AM) is a rare type of melanoma that accounts for 0.4% to 1.6% of total malignant melanomas. The incidence of AM increases over time, and it remains highly lethal, with a 5-year survival rate of 6% to 22%. Considering the rare nature of this disease, most studies on AM comprise isolated case reports and single-center trials, which could not provide comprehensive assessment of the disease. Therefore, we conducted a population-based study by using the Surveillance, Epidemiology, and End Results (SEER) program to provide the latest and best available evidence of AM.We extracted all cases of AM registered in the SEER database from 1973 to 2011 (April 2014 release) and calculated age-adjusted incidence. Only cases with active follow-up were included to predict factors associated with prognosis. Survival outcomes were also compared among different types of surgery.We identified 640 AM cases, which consisted of 265 rectal melanoma and 375 anal melanoma. The estimated annual incidence rates of AM per 1 million population were 0.259 in males and 0.407 in females, and it increased with advanced age and over time. Tumor stage and surgical treatment were independent predictors of survival. Results implied that surgery improved the prognosis of patients with local- and regional-stage AM but could not prolong the survival of patients with distant-stage AM. Moreover, the outcome of less extensive excision was not statistically different from that of more extensive excision.This study provides an up-to-date estimation of the incidence and prognosis of AM by using SEER data. The incidence of AM continuously increases over time, despite its rarity. This disease also exhibits poor prognosis. Thus, AM must be further investigated in future studies. We also recommend surgery as the optimal treatment for local- and regional-stage AM patients but not for those with distant metastasis.

[Primitive anorectal melanoma]

Nous proposons une étude rétrospective réalisée au sein du département de gastro-entérologie et d'Oncologie du CHU Casablanca colligeant tous les cas des mélanomes ano-rectaux primitifs, sur une période de 15 ans (du 1997 au 2012). Notre série comportait 14 patients, 8 hommes et 6 femmes avec une moyenne d’âge de 60,5 ans. Les signes cliniques étaient dominés par les rectorragies et le syndrome rectal (plus de 80% des malades). L'aspect tumoral noirâtre à été noté chez la moitié des malades. L'examen endoscopique a révélé une prédominance des lésions ulcéro-bourgeonnantes. Dans 5 cas la tumeur était plus haut située entre 5 à 8 cm de la marge anale. Le bilan d'extension avait décelé des métastases ganglionnaires, osseuses ou viscérales chez 7 malades. Un traitement chirurgical a été pratiqué chez 50% des malades (7 cas). Il a consisté en une exérèse locale isolée (2 cas) ou associée à une radiothérapie (2 cas) et une amputation abdomino-périnéale dans 3 cas. Quatre malades ont reçu une chimiothérapie et/ou radiothérapie palliative et dans deux cas on s'est contenté d'un traitement symptomatique. L’évolution a été marquée par une récidive chez les 2 patients traités par exérèse locale, dont un a été bénéficié d'une amputation abdomino-pelvienne de rattrapage et un des trois patients traités par chirurgie radicale. Deux patients sont en rémission complète après 36 mois de recul.

The first attempt in local excision of anorectal malignant melanoma using transanal endoscopic microsurgery

Anorectal malignant melanoma (AMM) is an uncommon malignancy that is thought to arise from melanocytes in the mucosa around the anorectal junction. AMM is commonly misdiagnosed, and definitive preoperative diagnosis is often difficult. The prognosis of AMM is relatively poor. Although radical resection is required for AMM, there is still no consensus at this moment on which surgical approach is preferred. We herein report a rare case of AMM which was treated by transanal endoscopic microsurgery (TEM) in combination with radiotherapy, which resulted in complete excision of the lesion without complications. The successful treatment for this AMM using TEM emphasizes the need to broaden its application in the treatment of various rectal lesions while preserving organ function and decreasing recurrence.

Anorectal malignant melanoma: retrospective analysis of management and outcome in a single Portuguese Institution

Anorectal melanoma is an uncommon cancer with a poor prognosis. We aim to describe the clinical presentation, treatment and outcome of patients with anorectal melanoma in our center. Retrospective study of patients with anorectal melanoma treated between 2000 and 2011 at a cancer center in Lisbon. Ten patients were identified, eight females and two males, with median age 70.5 years (32-79). Symptoms at presentation were rectal bleeding (8), anal pain (4) and discomfort (3). Tumor location was anal (6), rectal (3) and anorectal transition (2). Seven patients had surgery: abdomino-pelvic resection (5) and local resection (2). Among the two patients who underwent local resection, one was an incidental finding in a hemorrhoidectomy specimen. This patient had further adjuvant chemotherapy (dacarbazine). Three patients had distant metastasis at diagnosis, one had chemotherapy and two had best supportive care. Six of the seven operated patients relapsed in a median time of 5.4 months: distant metastasis (4), local recurrence (1), both (1). The two local relapse patients had surgical widening of resection margins (1) and radiotherapy (2). One-year survival was 30 %; 3-year survival was 20 %. Anorectal melanoma has a poor prognosis due to advanced disease at presentation and aggressive course, with relapse in almost all operated patients. Treatment guidelines have not been established due to the lack of randomized studies. However, recent studies show that sphincter-sparing surgical procedures along with low dose intensity radiotherapy seem to achieve a local control similar to abdomino-pelvic resection. No systemic therapy is considered standard of care for advanced disease, and regimens are extrapolated from cutaneous melanoma experience.