Melanoma of the anorectal region: the experience of the National Cancer Institute of Milano

Anorectal balloon cell melanoma: a rare variant

Balloon cell melanoma is a rare presentation of malignant melanoma, usually on the skin, with less than 100 cases reported. Mucosal BCM is even rarer, with only one case of anorectal BCM reported in English literature. The diagnosis is based on the histopathologic findings of a tumor composed of large, foamy melanocytes, with or without pigmentation, and confirmed by immunohistochemical studies showing expression for melanocytic markers. The foam cell appearance of the tumor cells and the lack of melanin pigment lead to a diagnostic dilemma, mostly when presented at an unusual location. Herein, we report a case of balloon cell melanoma at the anorectal junction in a 73-year-old male patient complaining of constipation and bleeding per rectum. Surgical resection was performed with no evidence of recurrence after three years of close follow-up. We believe this case will raise awareness among the medical community to consider this tumor a differential diagnosis in rectal masses.

Challenges in managing anorectal melanoma, a rare malignancy

INTRODUCTION AND IMPORTANCE

Anorectal melanoma is a rare and aggressive malignancy that can be difficult to diagnose due to its nonspecific presentation.

CASE PRESENTATION

We present a case of a 69-year-old woman who presented with painful defecation, bleeding per rectum, and a mass coming out of her anal opening. The initial differential diagnosis included hemorrhoids, rectal polyp, or a malignant lesion of the rectum. However, histopathological evaluation following transanal excision of the rectal mass revealed mucosal melanoma in the anorectal region. Further investigation showed no evidence of locoregional or distant metastasis.

CLINICAL DISCUSSION

Surgery remains the primary treatment option for anorectal melanoma, but complete resection is often not feasible, leading to high rates of local recurrence and distant metastasis. The incidence of metastatic disease at the time of presentation is high, and a multidisciplinary approach is necessary to manage these patients. Currently, standard systemic therapies used for cutaneous melanoma are the mainstay of treatment for metastatic anorectal melanoma, but there is a need for further research to develop tailored treatment strategies.

CONCLUSION

Our case report highlights the importance of considering anorectal melanoma in the differential diagnosis of patients presenting with anorectal symptoms. It emphasizes the need for a multidisciplinary approach to managing this rare malignancy. Early diagnosis, a multidisciplinary approach, and ongoing research into more effective treatments are crucial for improving outcomes for patients with anorectal melanoma.

Anorectal malignant mucosal melanoma

Anorectal mucosal melanoma (AMM) is a rare, aggressive malignancy. The symptoms of AMM mimic common benign conditions in the anus, such as haemorrhoids; hence diagnosis is often made late, a third of patients having metastasis at first presentation. Surgical resection remains the standard of treatment, and adjuvant therapy is varied, including immunotherapy, brachytherapy, and chemotherapy. The prognosis is poor, with a 5-year survival of 20%. A 65year old woman presented with a five-year history of symptoms suggestive of haemorrhoids and was diagnosed with a malignant anorectal mucosal melanoma after symptoms worsened and further investigation was performed. She underwent surgical resection and is currently receiving adjuvant therapy. The prognosis of AMM, the lack of consensus on the treatment regimen to date, and the need for a high index of suspicion for early diagnosis are discussed.

Funding

None declared.

Primary Malignant Melanoma of the Genitourinary System: A Systemic Review and Report of Eight Cases

Malignant melanoma (MM) of mucosal membranes (excluding anus and head-neck) is a rare but aggressive disease with poor outcomes. The knowledge of this tumor's development, etiology, and management is scarce, mainly due to the low case numbers. We presented eight cases and performed a comprehensive literature review on mucosal MM (between 1970 and 2020). We identified 47 manuscripts on 55 patients with primary mucosal MM (limited to urothelium and vagina) and reviewed demographics, tumor specifications (morphology, stage, etc.), management, and survival. We identified 10 manuscripts discussing treatment in 1595 mucosal and non-mucosal MM and extracted the data regarding the non-surgical treatment modalities of mucosal MM patients. In 63 cases, 48 tumors primarily occurred in the urothelium (urethra: 47, bladder: 1) and 15 in the vagina. Molecular studies in a subset of cases revealed alterations in c-KIT, NRAS, BRAF (non-V600E and V600E), TP53, and NF1. Fifty-three patients underwent surgery (with additional chemotherapy, immunotherapy, and radiotherapy in 19, eight, and eight patients, respectively). The outcome was available in 52 cases, showing 21 deaths, 10 without recurrence, two alive with disease, and five lost to follow-up. Shared genetic signatures in mucosal and skin MM suggest a similar development mechanism; however, unlike skin MM, there are less BRAF mutations and more PI3K/AKT/mTOR pathway alterations in mucosal MM. Prolonged chemotherapy (i.e., methotrexate) and immune-modulating agents (i.e., natalizumab) may be risk factors. The stage at diagnosis and proper surgical extirpation are keys to the prognosis and survival of patients.

Extensive resection improves overall and disease-specific survival in localized anorectal melanoma: A SEER-based study

Background

Anorectal melanoma is a rare tumor with a dismal prognosis. The only promising treatment for anorectal melanoma is surgery, either extensive resection (ER) or local excision (LE). However, the optimal extent of resection is still controversial. The purpose of this study was to investigate whether the survival outcomes of anorectal melanoma at different stages are influenced by the surgical approaches (LE or ER) using the National Institute of Health's Surveillance, Epidemiology, and End Results Program (SEER) database.

Methods

The Surveillance, Epidemiology and End Results (SEER) database was queried to identify patients treated for anorectal melanoma (2000–2018). Overall survival (OS) and disease-specific survival (DSS) outcomes were compared for the two surgical approaches (ER or LE) stratified by stage (localized, regional and distant).

Results

A total of 736 patients were included in the study. Details of previous surgical procedures were available for 548 of the study patients: 360 (65.7%) underwent LE, and 188 (34.3%) underwent ER. In localized cases, 199 underwent LE, and 48 underwent ER. The OS (median 45 vs. 29 months, 5-year rate 41.7% vs. 23.4%) and DSS (median 66 vs. 34 months, 5-year rate 51% vs. 30.7%) of patients undergoing ER were significantly better (p = 0.009 and 0.041, respectively) than those who received LE. Multivariate analysis showed that the type of surgery was an independent prognostic factor for both OS and DSS. Among the regional cases, 89 cases had LE, and 96 cases had ER. Patients with regional disease who underwent ER had no significant differences in OS (23 vs. 21 months; p = 0.866) or DSS (24 vs. 24 months; p = 0. 907) compared to patients who underwent LE. In distant cases, 72 cases had LE, and 44 cases had ER. Patients with metastatic disease who had ER also had similar OS (median 11 vs. 8 months; p = 0.36) and DSS (median 11 vs. 8 months; p = 0.593) to those who underwent LE.

Conclusion

Extensive resection can improve the long-term prognosis of localized anorectal melanoma compared to local excision, but the prognosis of the two surgical techniques is comparable in both regional patients and distant patients.

Is repeat wide excision plus radiotherapy of localized rectal melanoma another choice before abdominoperineal resection? A case report

BACKGROUND

Rectal melanoma is an uncommon neoplasm that accounts for approximately 1 percent of rectal cancer cases. Abdominoperineal resection was regarded as the radical procedure for disease control. Nevertheless, it led to more postoperative complications than sphincter-sparing wide local excision (WLE) and reduced the patient’s quality of life (QOL) owing to creation of colostomy. Therefore, in this study, WLE, radiotherapy (RT), and a second WLE were conducted on a patient who had been diagnosed with localized rectal melanoma.

CASE SUMMARY

The patient was a 79-year-old woman who had been experiencing anal pain and bloody stool for 1 mo. Colonoscopy, magnetic resonance imaging, positron emission tomography–computed tomography, and histological analysis of tissue biopsy using the histological markers Melan-A (+), S-100 (+), and Ki-67 (+, 50%) lead to the diagnosis of localized rectal melanoma. The patient had initially undergone WLE to resolve problem of anal bleeding, followed by RT to treat the residual lesion with partial response. Subsequently, the residual lesion was removed with margin-free resection by the second WLE. The patient’s postoperative course was smooth and uneventful. During the 2-year follow-up, no local recurrence was observed. Additionally, a good functional outcome and improved QOL were reported.

CONCLUSION

Combining WLE, RT, and repeat WLE is proposed as a viable alternative for treating rectal melanoma accompanied by bleeding symptoms that cannot be completely resected at the beginning.

Surgical treatment of anorectal melanoma: a systematic review and meta-analysis

Background

Anorectal melanoma is a rare neoplasm with a poor prognosis. The surgical approaches for anorectal melanoma can be categorized into local excision (procedures without lymph node removal and preservation of the rectum) and extensive resection (procedures with rectum and pararectal lymph node removal). The aim of this systematic review and meta-analysis was to compare the survival of patients who underwent extensive resection with that of patients who underwent local excision, stratifying patients according to tumour stage.

Methods

A literature review was performed according to PRISMA guidelines by searching MEDLINE/PubMed for manuscripts published until March 2021. Studies comparing survival outcomes in patients with anorectal melanoma who underwent local excision versus extensive resection were screened for eligibility. Meta-analysis was performed for overall survival after the different surgical approaches, stratified by tumour stage.

Results

There were 347 studiesidentified of which 34 were included for meta-analysis with a total of 1858 patients. There was no significant difference in overall survival between the surgical approaches in patients per stage (stage I odds ratio 1.30 (95 per cent c.i. 0.62 to 2.72, P = 0.49); stage II odds ratio 1.61 (95 per cent c.i. 0.62 to 4.18, P = 0.33); stage I–III odds ratio 1.19 (95 per cent c.i. 0.83 to 1.70, P = 0.35). Subgroup analyses were conducted for the time intervals (<2000, 2001–2010 and 2011–2021) and for continent of study origin. Subgroup analysis for time interval and continent of origin also showed no statistically significant differences in overall survival.

Conclusion

No significant survival benefit exists for patients with anorectal melanoma treated with local excision or extensive resection, independent of tumour stage.

Spectrum of presentation in primary anorectal malignant melanoma and its management

The article presents a series of four patients with primary anorectal melanoma presenting to our institute between 2016 and 2021. The primary objective of the series is to give an overview of the variable presentation of this rare entity from a high-volume colorectal tertiary care centre in a developing country. The patients ranged in age from 55 to 73 years and were mostly women (except one). The clinical presentation varied from bleeding per rectum to tenesmus and mucus in stools, overlapping with those of inflammatory bowel disease and primary anorectal adenocarcinoma. All patients were treated with surgery (laparoscopic or open), ranging from local excision to abdominoperineal resection. All our patients had a good outcome after surgery with no mortality at 30 or 90 days after surgery. The article aims to present a comprehensive overview of the various options of management with evidence from the surgical literature.

Safety and efficacy of electrochemotherapy in a series of patients with nonmetastasized primary or recurrent anorectal malignant melanoma

Anorectal malignant melanoma (AMM) is a rare malignant tumor. Surgery remains the gold standard but new adjuvant treatments to allow local sphincter-saving are warranted. Electrochemotherapy (ECT) is an alternative to surgery in selected cohorts of patients. To evaluate safety and efficacy of ECT in a retrospective series of patients with primary or recurrent AMM in terms of local disease control, local progression free and overall survival. Seven primary and one recurrent AMM underwent ECT. Patients were followed at 1 and 2 months and at the longest available follow-up with clinical examination and/or ultrasound. One month after ECT 6/8 (75%) patients showed complete response, 1/8 partial response (12.5%) and 1/8 stable disease (12.5%), confirmed at 2 months. Bleeding stopped in all patients, and pain was absent or mild/moderate in all patients. No serious adverse events were observed. At 1 year of follow-up seven out of eight patients were alive (87.5%), four were disease-free and three were alive with disease. At the longest available follow-up (mean 4.9 ± 2.0 years) five out of eight (62.5%) of patients were still alive. Our study showed that ECT is well tolerated and effective in the treatment of patients with anal melanoma with good local control of disease.

Genetic alteration of Chinese patients with rectal mucosal melanoma

Background

Rectal mucosal melanoma (RMM) is a rare and highly aggressive disease with a poor prognosis. Due to the rarity of RMM, there are few studies focusing on its genetic mechanism. This retrospective study aimed to analyze the genetic spectrum and prognosis of RMM in China and lay a foundation for targeted therapy.

Methods

36 patients with primary RMM from Peking University Cancer Hospital were enrolled in this study. The Next-generation sequencing (NGS) data of the tumor samples were fitted into the TruSight™ Oncology 500 (TSO500) Docker pipeline to detect genomic variants. Then, the univariate and multivariate Cox hazard analysis were performed to evaluate the correlations of the variants with the overall survival (OS), along with Kaplan-Meier and log-rank test to determine their significance.

Results

BRAF mutations, NRG1 deletions and mitotic index were significant prognostic factors in the univariate analysis. In multivariable analysis of the OS-related prognostic factors in primary RMM patients, it revealed 2 significant alterations: BRAF mutations [HR 7.732 (95%CI: 1.735–34.456), P = 0.007] and NRG1 deletions [HR 14.976 (95%CI: 2.305–97.300), P = 0.005].

Conclusions

This is the first study to show genetic alterations exclusively to Chinese patients with RMM. We confirmed genetic alterations of RMM differ from cutaneous melanoma (CM). Our study indicates that BRAF and NRG1 were correlated with a poor prognostic of RMM and may be potential therapeutic targets for RMM treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08383-6.

Amelanotic anorectal malignant melanoma in an ulcerative colitis patient: a rare coincidence or a rare association

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal system, known to be associated with increased risk of carcinogenesis. We report the case of a 55-year-old woman, presenting with symptoms of increased bowel frequency, per rectal bleeding and rectal pain with a background of ulcerative colitis (UC). This was presumptively managed as UC flare, with titration of her medications to control the symptoms. However, a flexible sigmoidoscopy revealed an ulceroproliferative lesion in the rectum, which was identified as an amelanotic anorectal malignant melanoma on immunohistochemistry. No local or distant metastases were noted on radiological imaging. The tumour enlarged progressively and was managed with laparotomy and defunctioning stoma followed by palliative chemotherapy and immunotherapy. This is the first such case reported in literature, highlighting the importance of endoscopic assessment and the need to consider other differential diagnosis in patients with symptoms of IBD flare.

Trends in the management of anorectal melanoma: A multi-institutional retrospective study and review of the world literature

BACKGROUND

Anorectal melanoma (ARM) is a rare disease with a poor prognosis. Evidence on optimal treatment is limited and surgical management varies widely. We hypothesized that the frequency of abdominoperineal resection used as primary treatment of ARM has decreased over the past several decades.

AIM

To update our understanding of outcomes for patients with ARM and analyze management trends around the world.

METHODS

This is a multi-institutional, retrospective study of patients treated for ARM at 7 hospitals. Hospitals included both large, academic, tertiary care centers and smaller, general community hospitals. Using prospectively maintained institutional tumor registries, we identified 24 patients diagnosed with ARM between January 2000 and May 2019. We analyzed factors prognostic for recurrence and survival. We then used Cox regression to measure overall survival (OS) and melanoma-specific survival. We also performed a literature review to assess trends in surgical management and outcomes.

RESULTS

Of the 24 patients diagnosed with ARM, 12 (50.0%) had local, 8 (33.3%) regional, and 4 (16.7%) distant disease at diagnosis. Median time to recurrence was 10.4 mo [interquartile range (IQR) 7.5-17.2] with only 2 patients (9.3%) not developing recurrence following surgical resection. Median OS was 18.8 mo (IQR 13.5-33.9). One patient is still alive without recurrence at 21.4 mo from diagnosis; no other patient survived 5 years. Primary surgical management with abdominoperineal resection (APR) vs wide excision (WE) did not lead to differences in OS [hazard ratio = 1.4 (95%CI: 0.3-6.8)]. Review of the literature revealed geographic differences in surgical management of ARM, with increased use of WE in the United States and Europe over time and more frequent use of APR in Asia and India. There was no significant improvement in survival over time.

CONCLUSION

There is wide variation in the management of ARM and survival outcomes remain poor regardless of approach. Surgical management should aim to minimize morbidity.

Metastatic anorectal melanomas - An exploratory retrospective analysis on the benefits of systemic therapy versus best supportive care in a resource-limited setting from India

Aim

Data regarding the optimal management of metastatic anorectal melanoma (mARM) is scarce. The primary aim was to evaluate the potential benefits of systemic therapy in mARM.

Materials and Methods

This is a retrospective analysis of all mARM who presented between July 2013 and June 2015 at the Department of GI Medical Oncology, Tata Memorial Hospital.

Results

Of a total of 37 patients, twelve patients were planned for best supportive care (BSC) only while the remaining 25 patients received systemic therapy. The median overall survival (OS) for the whole cohort was 27 weeks. The OS was significantly better in patients who received first-line therapy as compared to those who were offered BSC (median OS: 14 vs. 33 weeks; P = 0.04). Patients with PS of 1 did significantly better than PS of 2 more (OS 70 vs. 17 weeks; P = 0.015).

Conclusion

mARM should be offered chemotherapy, especially in good performance patients. Paclitaxel/Platinum or Capecitabine/Temozolomide regimens can be considered as the preferred regime in the resource-limited setting where immunotherapy may not be a feasible option.

Advances and Annoyances in Anus Pathology

Anal lesions are commonly mistaken clinically for prolapse or hemorrhoids but span a wide spectrum of disorders. Anal lesions include squamous, glandular, melanocytic, infectious, and lymphoid tumors. This article provides a broad overview of anal disorders and highlights specific issues that may hinder diagnosis.

Primary anorectal malignant melanoma with laparoscopic abdominoperineal resection: a case study and review of the relevant literature

ARMM is a disease with a poor prognosis. ARMM is often diagnosed at an advanced stage, and the 5-year survival rate of ARMM is < 20%. Although the number of case reports on ARMM is gradually increasing, the optimal treatment strategy for ARMM remains controversial. We report the case of an 81-year-old woman who had experienced bloody stool for 6 months before her diagnosis and who had been initially diagnosed with hemorrhoids. The pathological diagnosis of a biopsy specimen was malignant melanoma. Other examinations showed no evidence of lymph node or distant metastasis. Based on these results, laparoscopic abdominoperineal resection was performed. Three months later on her first follow-up examination, distant metastasis to the lung and liver was detected. Immunotherapy using Nivolumab was initiated to treat the recurrent disease. We reviewed the characteristics of a total of 1834 ARMM patients described in previous reports on ARMM for which the full text was available on PubMed. We experienced a case of ARMM. The prognosis of ARMM is still poor, regardless of the surgical procedure. Previous studies and our case report suggest that systemic therapy, such as immunotherapy using an anti-PD-1 ligand may be more important than reinforcement of local control for improving the prognosis of ARMM patients.

Less is more: A systematic review and meta-analysis of the outcomes of radical versus conservative primary resection in anorectal melanoma

INTRODUCTION

Anorectal melanoma (ARM) is a rare disease with a poor prognosis. There is no consensus as to the optimal primary surgical treatment for ARM, with advocates for both radical (abdominoperineal resection [APR]) and conservative strategies (wide local excision [WLE]). Here, we report a systematic review of studies comparing outcomes between these strategies.

METHODS

Studies comparing APR with WLE in patients with ARM were included, and a systematic review using the Grading of Recommendations, Assessment, Development and Evaluation methodology was performed. Outcomes deemed critical included overall survival, disease-free survival, local recurrence and quality of life.

RESULTS

Forty studies were identified, of which 27 were suitable for inclusion. Twenty-three studies compared overall survival between WLE and APR, with no difference in outcomes noted (risk ratio [RR]: 0.80, 95% confidence interval [CI]: 0.60-1.07, p = 0.13). Seven studies compared disease-free survival, with no difference in outcomes noted (RR: 1.08, 95% CI: 0.61-1.91, p = 0.79). A total of 19 studies compared local recurrence rates, with again no significant difference in outcomes noted (RR: 0.71, 95% CI: 0.44-1.14, p = 0.16). None of the studies identified reported quality of life-related outcomes.

CONCLUSION

There is no evidence to suggest that a radical primary surgical strategy improves outcomes in ARM. Therefore, given the well-documented morbidity associated with APR, WLE with regular surveillance for local recurrence should be the primary strategy in most patients.

Primary Dedifferentiated Amelanotic Anorectal Melanoma: Report of a Rare Case

Anorectal melanoma (ARM) is an uncommon aggressive malignancy that comprises 0.5% to 1.6% of all melanoma manifestations. Dedifferentiated melanoma is very rare with loss of all melanocytic differentiation markers and is usually seen in metastatic melanoma of cutaneous origin. In this article, we report the first case of primary dedifferentiated amelanotic ARM in a 68-year-old male who presented with anal discomfort that was initially treated as inflamed hemorrhoids. Physical examination revealed a large protruding anal mass, biopsy of which showed biphasic malignant tumor cells with distinct immunoprofiles: a superficial spindled/sarcomatoid component positive for SOX10 and S100, and a deeper epithelioid/rhabdoid component positive for desmin, AE1/AE3, and EMA. Both components were negative for HMB-45, Melan-A/MART-1, c-Kit, and other lineage markers. Molecular analysis by polymerase chain reaction demonstrated wild-type BRAF and KRAS genes. A diagnosis of dedifferentiated ARM was made based on the coexistence of a differentiated component (spindled: S100 and SOX10 positive) and a dedifferentiated component (epithelioid: all melanoma markers including S100 and SOX10 negative). Shortly afterwards, the patient developed extensive pulmonary and liver metastases and expired 20 days after the diagnosis was rendered, reinforcing the highly aggressive nature of this disease entity.

Multiple synchronous anorectal melanomas with different colors: A case report

BACKGROUND

Anorectal melanoma (AM) is an extremely rare malignant tumor originating from anorectal melanocytes with a poor prognosis. AM has been reported to have a much lower incidence than cutaneous or choroid melanoma, accounting for 0.4%-1.6% of all melanomas.

CASE SUMMARY

We report a 76-year-old female patient diagnosed with anorectal malignant melanoma by colonoscopy and biopsy. Intraoperative examination revealed two distinct anorectal tumors, one melanotic and another amelanotic, as well as two pigmented mucosal zones at the dentate line level. Abdominal perineal resection was performed. A pathological report confirmed all four lesions to be melanomas. Postoperatively, we followed an immunotherapy protocol targeting PD-1 (nivolumab). The patient had 24 mo of disease-free follow-up upon completion of nivolumab treatment.

CONCLUSION

This is the first reported case presenting coexistence of pigmented and unpigmented AMs in the same patient.

Primary Anorectal Amelanotic Melanoma: The First Case Report from Saudi Arabia

Anorectal melanomas are exceptionally uncommon and only 30% of anorectal melanomas are amelanotic. We report here a case of an anorectal amelanotic melanoma in a female patient. An 84-year-old patient complained of anal mass for 3 months. On examination, there was a 7.0 cm mass prolapsing through the anus that was pale-pink in color. Abdominal, pelvic, and chest computed tomography (CT) showed rectal wall thickening with an eccentric polypoid soft tissue density mass, and left inguinal and presacral lymph node enlargement along with a small nodule in the lower lobe of the left lung, likely representing metastatic deposit. Microscopic examination revealed a piece of skin with hyperplastic squamous epithelium with surface ulceration. The dermis and underlining tissue were showing infiltration by malignant sheets and nests of ovoid and spindle shape cells with prominent nucleolus and high mitotic s. Immuno-staining for HMB-45, S-100, and Melan-A was positive, and it was negative for P63, CK 5/6, and Pan-CK, thus confirming it as an anorectal amelanotic melanoma, and not an epithelial tumor. This is the first case of an amelanotic anorectal melanoma reported from Saudi Arabia.

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.

Prognostic factors in primary anorectal melanoma: a clinicopathological study of 60 cases in China

To investigate the clinicopathological features and prognostic factors of primary anorectal melanoma, we described the clinical presentations, histopathology, and prognosis of 60 cases in China. Patients' age ranged from 17 to 86 years, with a female-to-male ratio of 2.33:1. The prevalent anatomic site of tumor was the anorectum. The mean tumor thickness was 11.5 mm, and mean tumor size was 2.9 cm. Abdominoperineal resection was performed on 38 (63.3%) patients, whereas wide local excision was performed on 22 (36.7%) patients. Thirty-three (55.0%) patients were pathologically confirmed to have lymph node metastasis, and 9 (15%) patients had clinically distant metastasis at diagnosis. Histologically, epithelioid cell (91.7%) was the predominant cell type, followed by spindle (31.7%), pleomorphic (25.0%), and small round cell (5.0%). Solid sheet, nest, pseudopapillary, and pseudoalveolar growth patterns were noted in 45 (75.0%), 22 (36.7%), 13 (21.7%), and 6 (10.0%) cases, respectively. After a median follow-up of 44 months, the 5-year disease-specific survival rate was 33.3%. Age, tumor size, depth of invasion, tumor thickness, lymphatic metastasis, and lymphovascular and perineural invasion were significantly correlated with survival in univariate analysis. Multivariate analysis revealed that age greater than 70 years and tumor invasion beyond deep muscular layer/sphincter ani externus were independent poor prognostic factors. As the largest single-institution study of anorectal melanoma in an Asian population, we concluded that anorectal melanoma is a rare and lethal malignant neoplasm with morphologic diversity. Large population-based studies are still needed to establish an efficient staging system in evaluation of prognosis and facilitation of treatment for anorectal melanoma patients.

Anorectal melanoma: experience from a tertiary cancer care centre in South India

Introduction Mucosal malignant melanoma of the anorectum is a rare and aggressive disease, in which early diagnosis is difficult. The prognosis remains extremely poor, irrespective of the treatment. We share our experience in treating this malignancy at our centre in South India. Methods This study describes a retrospective analysis of 31 cases of anorectal melanoma presented to our centre between January 2001 and December 2013. Results Twenty-two patients (71%) presented with metastasis and had a median overall survival of nine months. None of the 22 patients survived for two years. Nine patients (29%) had curative surgery, in the form of abdominoperineal resection (six patients), abdominoperineal resection with bilateral inguinal node dissection (one patient), abdominoperineal resection with liver resection (one patient) and posterior exenteration (one patient). In patients who underwent curative surgery, the median overall survival was 15 months and disease-free survival was nine months, with a two-year overall survival of 22%. Conclusions Anorectal melanoma is an aggressive disease with a poor prognosis. The majority of patients present with distant metastases. Prognosis depends on stage at presentation. Early diagnosis and surgical resection may improve the overall outcome. Newer modalities such as immunotherapy and targeted therapies such as anti-CTLA4 monoclonal antibody and anti-programmed cell death protein 1 monoclonal antibodies have radically changed the management of mucosal melanoma and may, in the future, improve the overall prognosis of anorectal melanoma.

Anorectal mucosal melanoma

Anorectal melanoma is an uncommon and aggressive mucosal melanocytic malignancy. Due to its rarity, the pre-operative diagnosis remains difficult. The first symptoms are non-specific such as anal bleeding, anal mass or pain. Although anorectal melanoma carries a poor prognosis; optimal therapeutics strategies are unclear. Surgical resection remains the mainstay of treatment. The optimal surgical procedure for primary tumours is controversial and can vary from wide local excision or endoscopic mucosal resection (EMR) to an abdomino-perineal resection. A high degree of uncertainly exists regarding the benefit of radiation therapy or chemotherapy. The treatment of advanced melanoma is evolving rapidly with better understanding of the disease biology and immunology. Considerable effort has been devoted to the identification of molecular determinants of response to target therapies and immunotherapy.

Abdominal perineal resection or wilde local excision in primary anorectal malignant melanoma. Case report and review

Introduction

Primary anorectal malignant melanoma is a rare and aggressive tumor that carries a poor prognosis. Anorectal melanoma (ARM) is often misdiagnosed as hemorrhoids adenocarcinoma polips and rectal cancer. ARM spreads along sub-mucosal planes and is often to wide-spread for complete resection at time of diagnosis and almost all patients die because of metastases.

Presentation of the case

A 77-year-old male patient presented a history of recurrent rectal bleeding and whose histopathological diagnosis was melanoma.

Discussion

The treatment of choice remains controversial. Surgery with complete resection represents the typical treatment. However standard operative procedures related to the area of resection and lymph dissection have yet to be established. Abdominal perineal resection (APR) with or without bilateral inguinal lymphadenectomy or wide local excision (WLE) have been used to manage patients with ARM.

Conclusion

The higher serum levels of LDH and YKL-40 are suggestive for Anorectal Melanoma diagnosis. The decrease of these findings may be associated with good prognosis. The review of both APR and WLE options suggests no significant difference in survival among patients.

•

Anorectal melanoma (ARM) is a systemic disease.

•

Regardless how aggressive is ARM, no surgical treatment will truly change the outcome.

•

If surgical teqchniques are available, patients should undergo to wide local excision.

•

In case of recurrence, the abdominal resection should be considered as the best surgical treatment.

Extensive surgery and lymphadenectomy do not improve survival in primary melanoma of the anorectum: results from analysis of a large database (SEER)

AIM

Primary anorectal melanoma is a rare disease with a dismal prognosis due to early distant metastasis. The prognostic value of positive loco-regional lymph nodes and the impact of lymphadenectomy on overall survival are unclear. We have investigated this by analysis of data obtained from a national representative database, controlling for potential confounders.

METHODS

Data were retrieved from the Surveillance, Epidemiology and End Results (SEER) database. Multiple imputation analysis was performed to deal with missing data. Cox regression models were formulated using different prognostic factors including site of origin, gender, size, race, rate of lymph node metastasis (ratio between positive lymph node count and total lymph nodes harvested), extent of lymphadenectomy (none, level I etc.), age, type of surgery, stage of disease and administration of radiotherapy.

RESULTS

Our population was composed of 208 patients who underwent surgery between 1998 and 2012. Rate of lymph node metastasis (P = 0.027; hazard ratio 1.873, 95% CI 1.076-3.261) and race (P = 0.019; hazard ratio 2.291, 95% CI 1.148-4.575) were found to be independent predictors of survival.

CONCLUSION

Based on the data retrieved from the SEER database, metastasis to loco-regional lymph nodes is an important prognostic factor, but lymphadenectomy does not improve survival.

A case series of anal melanoma including the results of treatment with imatinib in selected patients

AIM

Anal melanoma is a rare malignancy with a poor prognosis.

METHOD

All patients with a diagnosis of anal melanoma treated at a single institution between 2000 and 2012 were identified and their treatment and outcome were evaluated.

RESULTS

Sixteen patients had a median survival of 2.9 years. Fourteen had Stage I or II disease with a median survival of 4.0 years and progression-free survival of 1.5 years. When used for disease staging, whole body positron emission tomography/CT identified an additional three sites of metastasis in five patients compared with CT of the chest, abdomen and pelvis. Surgery involved wide local excision or abdominoperineal excision with respective local recurrence rates of 50% and 66%. Eleven patients underwent testing for c-Kit mutations, of whom five were positive. Four of these were treated with the tyrosine kinase inhibitor imatinib, and showed rapid response of metastases outside the central nervous system.

CONCLUSION

The outcome of this malignancy remains poor. PET is the modality of choice for disease staging. Testing tumours for c-Kit mutations may allow selected patients to participate in trials of tyrosine kinase inhibitors.

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.

Balloon Cell Urethral Melanoma: Differential Diagnosis and Management

Introduction. Primary malignant melanoma of the urethra is a rare tumour (0.2% of all melanomas) that most commonly affects the meatus and distal urethra and is three times more common in women than men. Case. A 76-year-old lady presented with vaginal pain and discharge. On examination, a 4 cm mass was noted in the vagina and biopsy confirmed melanoma of a balloon type. Preoperative CT showed no distant metastases and an MRI scan of the pelvis demonstrated no associated lymphadenopathy. She underwent anterior exenterative surgery and vaginectomy also. Histology confirmed a urethral nodular malignant melanoma. Discussion. First-line treatment of melanoma is often surgical. Adjuvant treatment including chemotherapy, radiotherapy, or immunotherapy has also been reported. Even with aggressive management, malignant melanoma of the urogenital tract generally has a poor prognosis. Recurrence rates are high and the mean period between diagnosis and recurrence is 12.5 months. A 5-year survival rate of less than 20% has been reported in balloon cell melanomas along with nearly 20% developing local recurrence. Conclusion. To the best of our knowledge, this case is the first report of balloon cell melanoma arising in the urethra. The presentation and surgical management has been described and a literature review provided.

Abdominoperineal resection provides better local control but equivalent overall survival to local excision of anorectal malignant melanoma: a systematic review

OBJECTIVE

To determine whether the extent of surgery is associated with survival in anorectal malignant melanoma (ARMM).

BACKGROUND

ARMM is a rare and highly malignant neoplasm with unfavorable prognosis. The optimal surgical management, abdominoperineal resection (APR) or local excision (LE), has been long debated, but conclusive evidence has not been obtained.

METHODS

A comprehensive electronic literature search was performed to identify studies evaluating survival between APR and LE for ARMM. The main outcome measures were overall survival, relapse-free survival, and local recurrence. A meta-analysis was performed using the random-effects models to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Thirty-one studies, with a total of 1006 patients [544 (54.1%) APR and 462 (45.9%) LE], were included. Meta-analyses showed that overall survival (OR, 1.14; 95% CI, 0.74-1.76; P = 0.54) and relapse-free survival (OR, 0.95; 95% CI, 0.43-2.09; P = 0.89) did not differ significantly between the APR and LE groups. APR significantly reduced local recurrence compared with LE (OR, 0.18; 95% CI, 0.09-0.36; P < 0.00001).

CONCLUSIONS

Although several limitations, such as inclusion of only retrospective studies with relatively small sample size and selection biases for surgical procedure, are involved, this meta-analysis suggested that APR has no survival benefit; however, APR confers better local control than LE. Given that local failures after LE could be managed by salvage surgery, minimizing morbidity and maximizing quality of life should be the focus in surgical treatment of ARMM.

Primary anorectal malignant melanoma treated with endoscopic mucosal resection

Anorectal melanoma is a rare neoplasm that accounts for less than 1-4% of anorectal malignant tumors. The main therapeutic modality for anorectal melanoma is surgical treatment, with abdominoperineal resection or wide local excision being the most common approaches. A 77-year-old male with a history of cerebral infarction and hypertension presented with anal bleeding. Here, we report a case of anorectal melanoma treated by endoscopic mucosal resection with adjuvant interferon therapy rather than surgical resection. The patient has been disease-free for 5 years after endoscopic treatment.

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.

The role of radiation therapy in melanoma

Although melanoma was historically thought to be radiation resistant, there are limited data to support the use of adjuvant radiation therapy for certain situations at increased risk for locoregional recurrence. High-risk primary tumor features include thickness, ulceration, certain anatomic locations, satellitosis, desmoplastic/neurotropic features, and head and neck mucosal and anorectal melanoma. Lentigo maligna can be effectively treated with either adjuvant or definitive radiation therapy. Some retrospective and prospective randomized studies support the use of adjuvant radiation to improve regional control after lymph node dissection for high-risk nodal metastatic disease. Consensus on the optimal radiation doses and fractionation is lacking.

Primary amelanotic melanoma of the rectum mimicking adenocarcinoma

Patient: Male, 55

Final Diagnosis: Melanoma

Symptoms: Worsening constipation • tenesmus • weight loss

Medication: —

Clinical Procedure: Chemoradiation therapy

Specialty: Oncology

Phase II randomized trial comparing high-dose IFN-α2b with temozolomide plus cisplatin as systemic adjuvant therapy for resected mucosal melanoma

PURPOSE

Mucosal melanoma is rare and associated with extremely poor prognosis. However, standard adjuvant therapy for mucosal melanoma has not been established. We conducted a randomized phase II clinical trial in patients with resected mucosal melanoma to compare the efficacy and safety of high-dose IFN-α2b (HDI) and temozolomide-based chemotherapy as adjuvant therapy.

EXPERIMENTAL DESIGN

Patients with mucosal melanoma in stage II/III after surgery were randomized into three groups: observation group (group A, surgery alone), HDI group (group B, treated with 15 × 10(6) U/m(2)/d IFN-α2b, followed by 9 × 10(6) U IFN-α2b), and temozolomide (200 mg/m(2)/d) plus cisplatin (75 mg/m(2)) group (group C). The endpoints were relapse-free survival (RFS), overall survival (OS), and toxicities.

RESULTS

One hundred and eighty-nine patients were enrolled and finally analyzed. With a median follow-up of 26.8 months, the median RFS was 5.4, 9.4, and 20.8 months for group A, B, and C, respectively. Estimated median OS for group A, B, and C was 21.2, 40.4, and 48.7 months, respectively. Patients treated with temozolomide plus cisplatin showed significant improvements in RFS (P < 0.001) and OS (P < 0.01) than those treated with either HDI or surgery alone. Toxicities were generally mild to moderate.

CONCLUSION

Both temozolomide-based chemotherapy and HDI are effective and safe as adjuvant therapies for resected mucosal melanoma as compared with observation alone. However, HDI tends to be less effective than temozolomide-based chemotherapy for patients with resected mucosal melanoma in respect to RFS. The temozolomide plus cisplatin regimen might be a better choice for patients with resected mucosal melanoma.

Management of anorectal melanoma: report of 17 cases and literature review

BACKGROUND

Primary anorectal melanoma is a rare and aggressive disease. It accounts for 0.5% of all rectal tumors. They are very agressive tumors with poor prognosis. The aim of this study is to report the clinical and evolutionary profile and therapeutical approach of these tumors.

PATIENTS AND METHODS

A retrospective study of 17 patients with anorectal melanoma diagnosed between January 1998 and December 2007 was performed. The signs and symptoms, diagnostic study, and surgical and medical treatments were analyzed.

RESULTS

The average age was 58 years. Sex ratio was 12 men per five women. Patients had symptoms present for an average of 6 months. The most common symptom was rectal bleeding. According to Slingluff classification, five patients had stage I (localized tumor), four cases had stage II (regional nodes metastasis), and eight cases had stage III (distant metastasis). Seven patients have radical surgery. Only two patients received adjuvant immunotherapy. Eight patients received palliative chemotherapy based on dacarbazine or cisplatinum. The median survival was 8 months.

CONCLUSION

Prognosis of anorectal melanoma is still very poor. However, some patients when treated by radical resection may experience long-term survival. The use of adjuvant immunotherapy needs large collaborative studies in view of the rarity of the tumor.

A Systematic Review of Prognosis and Therapy of Anal Malignant Melanoma: A Plea for More Precise Reporting of Location and Thickness

Anal malignant melanoma (AMM) is a rare tumor with poor prognosis. We performed a systematic review of reports on wide local excision (WLE) and abdominoperineal resection (APR) for treatment of AMM in an attempt to define a precise set of reporting measures for outcomes of treatment of AMM. A systematic review of the literature was performed. Demographic data, surgical treatment, pathology, and survival rates were recorded. We compared WLE versus APR in terms of the overall survival time, the disease-free survival, and overall survival at 60 months. Twenty-one reports met the inclusion criteria. Notably, of these, 10 did not specify thickness of the primary melanoma. Interestingly, groin lymph node status was described in 19 of 21 reports, whereas location was specified in only 12 papers and thickness (depth in mm) in only 11. The median survival times of patients undergoing WLE (n = 324) and those undergoing APR (n = 369) are comparable (20 and 21 months, respectively). The mean median survival at 60 months was 15 per cent for WLE and 14 per cent for APR. The mean disease-free survival at 60 months was found to be 10 per cent for WLE and 6 per cent for APR. Patient selection for such a rare neoplasm yields very similar outcomes for both conservative and radical treatments. There is a wide variation in the reporting of both clinical and treatment outcomes. More uniformity of reporting of pathologic features and node status is essential before rational assessment of results can be done.

Anorectal melanoma: diagnosis and treatment

An increase in the incidence of anorectal melanoma has recently been noted in the United States. Anorectal melanoma is an uncommon and lethal condition, with a median survival of <20 months. Unfortunately, nonspecific symptoms also attributable to common and benign conditions (eg, hemorrhoids) cause significant delay in its diagnosis. Although it has not been validated by clinical trials, abdominoperineal resection has historically been the treatment of choice for this disease. However, for the past 2 decades, a lack of clear survival benefit has led to a shift toward less-mutilating wide local excisions. Controversy still exists regarding the benefit of radiation therapy and chemotherapy. Furthermore, the value of nodal surgery in anorectal melanoma is unclear. In this article, we review the history and current status of management of anorectal melanoma, with a particular focus on surgical controversies and challenges in optimizing survival.

Sphincter-sparing local excision and hypofractionated radiation therapy for anorectal melanoma: a 20-year experience

BACKGROUND

Anorectal melanoma is a rare disease with a poor prognosis. Because survival is determined by distant failure, many centers have adopted sphincter-sparing excision for primary tumor control. However, this approach is associated with high rates of local failure (∼50%). In this study, the authors report their 20-year experience with sphincter-sparing excision combined with radiation therapy (RT) for the treatment of localized anorectal melanoma.

METHODS

The authors reviewed the records of 54 patients with localized anorectal melanoma who were treated at the University of Texas MD Anderson Cancer Center from 1989 to 2008. All patients underwent definitive local excision with or without sentinel lymph node biopsy or lymph node dissection. RT (25-36 grays in 5-6 fractions) was delivered to extended fields that targeted the primary site and draining pelvic/inguinal lymphatics in 39 patients and to limited fields that targeted only the primary site in 15 patients.

RESULTS

The 5-year rates of local control (LC), lymph node control (NC), and sphincter preservation were 82%, 88%, and 96%, respectively. However, because of the high rate of distant metastasis, the overall survival (OS) rate at 5 years was only 30%. Although there were no significant differences in LC, NC, or OS based on RT field extent, patients who received extended-field RT had higher rates of lymphedema than patients who received limited-field RT.

CONCLUSIONS

The current results indicated that combined sphincter-sparing local excision and RT is a well tolerated approach that provides effective LC for patients with anorectal melanoma. Inclusion of the inguinal lymph node basins in the RT fields did not improve outcomes and was associated with an increased risk of lymphedema.

Anorectal malignant melanomas: Retrospective experience with surgical management

AIM: To present the experience and outcomes of the surgical treatment for the patients with anorectal melanoma from the Cancer Hospital, Chinese Academy of Medical Sciences.

METHODS: Medical records of the diagnosis, surgery, and follow-up of 56 patients with anorectal melanoma who underwent surgery between 1975 and 2008 were retrospectively reviewed. The factors predictive for the survival rate of these patients were identified using multivariate analysis.

RESULTS: The 5-year survival rate of the 56 patients with anorectal melanoma was 20%, 36 patients underwent abdominoperineal resection (APR) and 20 patients underwent wide local excision (WLE). The rates of local recurrence of the APR and WLE groups were 16.13% (5/36) and 68.75% (13/20), (P = 0.001), and the median survival time was 22 mo and 21 mo, respectively (P = 0.481). Univariate survival analysis demonstrated that the number of tumor and the depth of invasion had significant effects on the survival (P < 0.05). Multivariate analysis showed that the number of tumor [P = 0.017, 95% confidence interval (CI) = 1.273-11.075] and the depth of invasion (P = 0.015, 95% CI = 1.249-7.591) were independent prognostic factors influencing the survival rate.

CONCLUSION: Complete or R0 resection is the first choice of treatment for anorectal melanoma, prognosis is poor regardless of surgical approach, and early diagnosis is the key to improved survival rate for patients with anorectal melanoma.

Treatment and outcomes of anorectal melanoma

INTRODUCTION

anorectal melanoma is an uncommon disease constituting less than 3% of all melanomas. Due to its rarity, there are a lack of randomized control trials regarding appropriate management and current evidence is based mainly on retrospective studies.

METHODS

in view of the controversial surgical treatment of anorectal melanoma, we review the most published literature in an attempt to elucidate its typical clinical features along with current thinking with respect to management approaches to this aggressive disease. Using the keywords "anorectal" and "malignant melanoma", a medline search of all articles in English was performed and the relevant articles procured. Additional references were retrieved by cross reference from key articles.

RESULTS

anorectal melanoma affects the elderly with a slight preponderance for females. It commonly presents disguised as benign disease with local bleeding or suspicion for haemorrhoidal disease. There is no convincing evidence to indicate that radical resection of primary anorectal melanoma is associated with improvement in local control or survival, and local excision is an acceptable treatment option.

CONCLUSION

optimum management depends on several factors and the therapeutic goals should be to lengthen survival and preserve quality-of-life. Given that wide local excision is a more limited intervention with comparable survival it should be considered as the initial treatment choice. Unfortunately prognosis for patients with this disease remains poor despite choice of treatment strategy with overall five year disease-free survival less than twenty percent in most studies.

Malignant melanoma of the anorectum--a rare entity

OBJECTIVE

Primary anorectal melanoma is a rare entity with a poor prognosis accounting for approximately 0.1-4.6% of anal tumours and 0.5-1.6% of all melanomas. Almost 60% of patients have already disseminated disease at initial diagnosis.

METHOD

We report four cases of anorectal melanoma treated at our department from November 2006 to September 2008, as well as a review of the literature.

RESULTS

There were two females and two males, of median age 69 years (range: 59-81 years). Most frequent complaints were rectal bleeding and/or anorectal pain. Three of our four patients had amelanotic melanomas. We found the positive expression of S-100 protein and HMB-45 in two patients and melanin A cells in one case. Abdominoperineal resection was performed in two patients, colostomy in one patient and a wide local excision also in one case. Three patients died on account of dissemination of melanoma, one patient is still alive.

CONCLUSION

Anal melanoma remains a deadly problem. Clear guidelines for the therapy of anorectal melanoma have not been established. This mainly results from the rarity of this tumour. Treatment is based on retrospective studies, which report a limited number of cases.

A striking response of anorectal melanoma to radiotherapy (locoregional disease confined to perineum and anal canal)

Anorectal melanoma is a rare disease with an exceedingly poor prognosis. Literature evaluating outcomes is often difficult because of the infrequent diagnosis, delayed presentation and almost universally poor outcome. We describe a case of a 78-year-old woman with a large anorectal melanoma without detectable metastasis following radiological investigation. Due to the patient's co-morbidity, radiotherapy of 36 Gy once weekly over 7 weeks, was given as the sole treatment. The clinical outcome showed a remarkable regression of the tumour without radiological or clinical recurrence at 12 months' follow-up. This is the first case of the successful use of radiotherapy alone in anorectal melanoma.