Anorectal malignant melanomas: Retrospective experience with surgical management

Multidisciplinary Management of Anorectal Melanoma: a Retrospective Analysis of Surgical and Systemic Therapies from the National Cancer Database

PURPOSE

Anorectal melanoma (ARM) represents a problematic scenario due to a 5-year overall survival (OS) rate below 20% and its increasing incidence. Due to its comparable OS, local surgery (LS) has replaced radical surgery (RS). Adjuvant chemotherapy (Adj-CHT) and adjuvant immunotherapy (Adj-IT) are common treatments for ARM, while neoadjuvant immunotherapy (Neo-IT) has not been investigated yet. This study aimed to determine the best treatment to improve the OS.

METHODS

Patients with non-metastatic ARM in the National Cancer 1Database (2011-2021) who underwent surgery and received Neo-IT, Adj-IT, or Adj-CHT were included. Two cohorts were created based on the surgical approach (LS or RS). In their respective cohorts, patients receiving Neo-IT, Adj-IT, or Adj-CHT were matched 1:1:1 based on age, tumor size and location, lymphovascular invasion, and nodal disease. Kaplan-Meier analyses compared the different groups' influence on the 3-year OS.

RESULTS

Sixty patients were included in the LS cohort. Among them, there was no difference in the 3-year OS at the Kaplan-Meier analysis (Neo-IT 61%, Adj-IT 47.1%, and Adj-CHT 44%). Thirty-six patients were included in the RS cohort. Kaplan-Meier analysis for this group revealed that Neo-IT was a protective factor for 3-year OS (Neo-IT 71%, Adj-IT 11%, Adj-CHT 8%; p-value = 0.002).

CONCLUSION

Neo-IT + RS seems to improve the 3-year OS compared to the other common treatments for ARM. Neo-IT + RS can be considered a valuable treatment since prospective trials are challenging for rare diseases. When RS is not feasible, Neo-IT + LS may be beneficial as the 3-year OS reaches 61%.

A 22-year experience of surgical management of anorectal melanoma: risk factors for recurrence and death

PURPOSE

Anorectal melanoma (ARM) poses a significant challenge due to the lack of established guidelines and a 5-year overall survival rate of less than 20%. The only recognized death risk factors are positive lymph nodes and positive surgical margins. This study aimed to identify the risk factors for local/distant recurrences and death in a 22-year multi-institutional experience.

METHODS

All patients who underwent curative surgical resection or were referred to after resection at the Mayo Clinic for non-metastatic ARM (2002-2024) were included. Risk factors for local/distant recurrences, and deaths were assessed through multivariable Cox regression.

RESULTS

Eighty-eight patients were included in the study. Seventy-eight percent of patients had anal melanoma and 22% rectal melanoma. Nineteen percent had clinically positive lymph nodes. The surgical margins were positive in 62% of local surgeries, while they were positive in 13% of radical surgery cases. The first recurrence was often a local recurrence (67%), followed by distant metastasis (21%), with an overall comparable overall survival between the two. Radiotherapy administration, radical surgery, and negative margins were associated with less local recurrence. Clinically positive lymph nodes and local recurrences increased the risk of developing distant metastasis over time. Clinically negative lymph nodes, radiotherapy administration, radical surgery, and negative margins all contributed to a reduced death risk.

CONCLUSION

Local recurrences in ARM may influence distant metastasis and death more than what was previously believed. Positive surgical margins in local surgery were remarkably high, reaching 62%. Protective factors for local recurrence and death included radical surgery, negative surgical margins, and radiotherapy.

Mucosal melanoma: Review from a pathologist point of view

Mucosal melanomas (MuM) are rare malignant tumors arising from the epithelia lining the inner mucosal surfaces of the body. Unlike cutaneous melanoma, understanding of MuM is limited among pathologists and clinicians alike, primarily due to rarity of these tumors. MuM are characterized by genetic alterations quite distinct from cutaneous melanomas; however, their causative and promoting factors are unknown. These melanomas are characteristically diagnosed at a later stage due to their occult locations, leading to a worse prognosis. Dedicated staging systems for MuM exist only for sinonasal and conjunctival melanomas. Risk stratification of patients with MuM, particularly those arising from the anogenital area, is challenging. Recent studies have shown that minor modifications of the American Joint Committee on Cancer eighth edition cutaneous melanoma staging system can group patients fairly robustly; however, the proposed T-categorization systems have yet to be validated in larger cohorts. We summarize the demographic, clinical, histopathologic, and molecular features of common subtypes of MuM and highlight the outstanding needs in this field.

Can transrectal ultrasonography distinguish anorectal malignant melanoma from low rectal adenocarcinoma? A retrospective paired study for ten years

BACKGROUND

Anorectal malignant melanoma (ARMM) and low rectal adenocarcinoma (LRAC) have some similarities in clinical behaviors, histopathological characteristics and ultrasonographic findings, diagnostic errors are common. By comparing the transrectally ultrasonographic features between the two tumors, we propose to provide more possibilities in differentiating them.

METHODS

The data of 9 ARMMs and 27 age- and gender-matched LRACs (the lower margin below the peritoneal reflection) in West China Hospital Sichuan University between April 2008 and July 2019 were retrospectively reviewed. The ultrasonic features between the two groups were compared.

RESULTS

Transrectal ultrasonography (TRUS) showed that the length of ARMM was shorter than that of LRAC (28.22 ± 12.29 mm vs. 40.22 ± 15.16 mm), and ARMM had a lower position than that of LRAC (the distance to anal verge was 50.78 ± 11.70 vs. 63.81 ± 18.73 mm). Unlike LRAC, the majority of ARMM in our study was confined to the intestinal mucosa/submucosa (66.67/25.93%) (P < 0.05).

CONCLUSIONS

Based on the data of our study, several ultrasonographic findings (length, invasion depth, and position) of ARMM were significantly different from LRAC. Accordingly, more attention should be paid to masses at anorectal junction with lower position, shorter length, and shallower infiltration depth. Instead of the most common tumor, LRAC, ARMM should be taken into account to avoid a misdiagnosis, which will result in a poorer prognosis.

Clinicopathological profile and outcomes of anorectal melanoma from a tertiary care center in India

Background:

Anorectal melanoma (AM) is a rare subtype of melanoma.

Aim:

To study the clinic–pathologic features and outcomes in patients with AM.

Materials & methods:

Clinical, pathologic findings and outcomes of patients with AM were recorded.

Results:

Twenty-seven patients with AM were identified with median age of 57 years. Most patients presented in stage III (44.4%). Lymph node involvement was seen in 70.4%. The response to chemotherapy and immunotherapy was 16.6 and 25.0%, respectively. At a median follow up of 11 months, median overall survival was 30 months. Ballantine stage 3 and weight loss at presentation were predictors of poor survival.

Conclusion:

AM presents at an advanced stage with lymph node and distant metastasis.

Anorectal melanoma is a rare subset of melanoma presenting at an advanced stage with lymph node and distant metastasis. Early disease is managed surgically; however, optimal treatment of advanced disease is unclear. The stage at diagnosis is the most important prognostic factor. Prognosis is poor, but with the advent of targeted therapy and immunotherapy, the outcomes are improving.

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.

Primary anorectal malignant melanomas: retrospective analysis of 11 cases in a single center

Objectives

Anorectal malignant melanoma is a rare tumor with poor prognosis. In this study, it was aimed to present our surgical results by reviewing the literature retrospectively in 11 patients who underwent surgery for ARMM in our clinic.

Material and Methods

The patients who underwent surgery for anorectal malignant melanoma in Yuksek İhtisas Training and Research Hospital between 2007-2018 were included in the study.

Results

Four patients were males and seven were females. Mean age was 54.18. The tumor was in the rectum in 4 cases, in the anorectal region in 3 cases and in the anal canal in 4 cases. Wide local excision was performed in 3 cases and APR was performed in 8 cases. Four of the cases were stage I, 6 were stage II and 1 was stage III. Mean tumor size was 4.73 cm, and mean tumor depth was 13.6 mm. Mean number of metastatic lymph nodes was 10.37. Median survival was 12 months.

Conclusion

Anorectal malignant melanoma is a type of tumor diagnosed in late and advanced stages due to lack of specific findings. Although ARMM is rare, when rectal bleeding, pain, hemorrhoids and changes in bowel habits are observed, ARMM should be kept in mind.

Mucosal Melanomas of the Anogenital Tract: Clinical and Pathologic Predictors of Patient Survival

Primary anogenital mucosal melanomas (AGMs) are rare aggressive malignancies that are typically diagnosed at an advanced stage. Ulceration is a common feature in AGMs and may not correlate with outcome. Therefore, staging of AGMs similar to primary cutaneous melanomas, based on tumor thickness and ulceration, may not robustly predict outcome. Derivation of site-specific staging systems is essential for prognostication and optimal management of these patients. To this end, recent retrospective studies have revealed tumor thickness (TT) and mitotic rate (MR) as features of most prognostic significance as follows: in anorectal (TT only) and vulvar (TT and MR) melanomas.

Anorectal melanoma – histopathological and immunohistochemical features and treatment

Anorectal melanomas should be characterized by location (anal, rectal and anorectal), color, size, shape and mobility and microscopically, by melanocyte subtypes, grade of melanin pigmentation, junctional changes in the squamous epithelium, atypical mitotic index, cellular atypia, inflammatory infiltrate, vascular and perineural invasion, sentinel lymph node, and anorectal parietal penetration. Anorectal melanomas must be staged by American Joint Committee on Cancer (AJCC) and/or TNM Classification of Malignant Tumours (TNM) criteria. As melanocytes can present with several shapes, sometimes the differential diagnosis with other tumors in this region may be difficult. Because of this, immunohistochemistry is mandatory to attain a precise diagnosis. This study is a report of 14 patients with anorectal melanoma, in whom histological examinations were remade and immunohistochemistry was performed with several markers for melanocytes and for other tumor cells of the anorectal region, properly establishing the diagnosis. The most rational surgery is the extended local resection, when the disease is restricted to the area or the abdominoperineal resection to advanced lesions. Regardless of the technique used, the results are always poor. The authors deny any efficacy of current radio and/or chemotherapy as part of treatment of anorectal melanoma. Target-therapy for metastatic disease has been considered a good strategy, but the results are still inconclusive.

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.

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.

Early primary anorectal malignant melanoma treated with endoscopic submucosal dissection: a case report

BACKGROUND

Anorectal malignant melanoma (ARMM) is a rare disease accounting for less than 1% of primary anorectal malignancies. Here we first present a case of early primary anorectal malignant melanoma completely resected by endoscopic submucosal dissection (ESD).

METHODS AND RESULTS

A 43-year-old woman visited our hospital because of suspected anal melanoma found by routine colonoscopy in her local hospital. Following series of tests including CT, MRI, and whole-body PET-CT did not show any evidence of metastasis. The lesion was removed by the method of ESD in en bloc and no delayed bleeding or perforation occurred. The result of histopathologic examinations confirmed to be malignant melanoma. No recurrence or distant metastases were found during follow-up time (the latest follow-up was 2 years after ESD).

CONCLUSION

The present case showed endoscopic submucosal dissection that can be an effective and safe alternative treating early primary anorectal malignant melanoma.

Prognostic model for patient survival in primary anorectal mucosal melanoma: stage at presentation determines relevance of histopathologic features

Pathological staging of primary anorectal mucosal melanoma is often performed according to the American Joint Commission on Cancer (AJCC) guidelines for cutaneous melanoma, as an anorectal melanoma-specific staging system does not exist. However, it remains unknown whether prognostic factors derived for cutaneous melanoma also stratify risk in anorectal melanoma. We retrospectively determined correlations between clinicopathological parameters and disease-specific survival in 160 patients. Patients were grouped by clinical stage at presentation (localized disease, regional or distant metastases). Cox proportional hazards regression models determined associations with disease-specific survival. We also summarized the somatic mutations identified in a subset of tumors analyzed for hotspot mutations in cancer-associated gene panels. Most of the patients were white (82%) and female (61%). The median age was 62 years. With a median follow-up of 1.63 years, median disease-specific survival was 1.75 years, and 121 patients (76%) died of anorectal melanoma. Patients presenting with regional (34%) or distant metastases (24%) had significantly shorter disease-specific survival compared to those with disease localized to the anorectum (42%). Of the 71 anorectal melanoma tumors analyzed for hotspot genetic alterations, somatic mutations involving the KIT gene (24%) were most common followed by NRAS (19%). Increasing primary tumor thickness, lymphovascular invasion, and absence of regression also correlated with shorter disease-specific survival. Primary tumor parameters correlated with shorter disease-specific survival in patients presenting with localized disease (tumor thickness) or regional metastases (tumor thickness, absence of regression, and lymphovascular invasion), but not in patients presenting with distant metastases. Grouping of patients according to a schema based on modifications of the 8th edition AJCC cutaneous melanoma staging system stratified survival in anorectal melanoma. Our findings support stage-specific associations between primary tumor parameters and disease-specific survival in anorectal melanoma. Moreover, the AJCC cutaneous melanoma staging system and minor modifications of it predicted survival among anorectal melanoma patients.

Long-term Oncologic Outcome and Its Relevant Factors in Anal Cancer in Korea: A Nationwide Data Analysis

Purpose

Anal cancer is a rare disease in Korea, and thus survival analyses are limited by small sample sizes. This study used the Korea Central Cancer Registry (KCCR) for a survival analysis and for assessing characteristics of anal cancer in a large sample of Koreans.

Methods

From the KCCR, data on 3,615 patients who were diagnosed and treated for anal cancer from 1993 to 2015 were retrieved. Clinicopathologic variables including age, sex, histological type, and Surveillance Epidemiology and End Results (SEER) stage were reviewed, and a survival analysis was performed according to these variables.

Results

The 5-year relative survival rate improved from 39.7% in 1993–1995 to 66.5% in 2011–2015. Squamous cell carcinoma was the most common and showed the highest survival rate. Males and older patients (≥40 years and ≥70 years) showed poor prognoses.

Conclusion

The survival rate for anal cancer in Korea has improved steadily over time. The characteristics related to survival were the histological type, sex, and age. These statistics will be fundamental for future Korean anal cancer research.

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.

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.

Anorectal Malignant Melanoma: Retrospective Analysis of Six Patients and Review of the Literature

Malignant melanomas are rare aggressive tumours originating from the pigment-producing melanocytes. In our study, a review of the literature and a retrospective analysis of patients undergoing surgery at our clinic due to anorectal malignant melanoma were performed. The information of 6 patients undergoing surgery in our clinic due to anorectal malignant melanoma between January 2010 and January 2018 was retrieved retrospectively. The patients were assessed regarding demographic data, physical examination and imaging findings, the surgical method performed, postoperative complication, histopathological findings, oncological treatment and follow-up results. Four of the patients were female and 2 were male and the mean age was 61.6 (46–83) years. Two patients (33%) had liver metastases at the time of initial presentation. Abdominoperineal resection (APR) was performed in all patients 3 with laparoscopic method. The mean length of hospital stay was recorded to be 6.5 ± 1 days (5–12 days). Adjuvant chemotherapy and radiotherapy were administered in all patients. Also, interferon treatment was administered in one patient additionally. During the follow-up, 4 patients died due to extensive metastatic disease determined approximately in the 13th month. Two patients with regular follow-up are well and free of disease and their mean postoperative lifetime has been determined to be 12.5 months (6–26 months). Anorectal malignant melanomas (ARMM) are rare but aggressive tumours. The treatment should be focused on minimizing morbidity and maximizing the quality of life and function while removing the gross tumour.

Anorectal melanoma treated with abdominoperineal resection

The diagnosis of primary malignant melanoma of the anorectum is extremely rare and carries a very poor prognosis. While it is the third most common site of a primary melanoma, it accounts for <1% of anorectal malignancies. We present cases of anorectal melanoma treated with abdominoperineal resection.

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.

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.

Synchronous Primary Anorectal Melanoma and Sigmoid Adenocarcinoma

A primary anorectal malignant melanoma is a rare tumor. Moreover, cases involving a synchronous anorectal melanoma and colon adenocarcinoma are extremely rare. The authors report a case of a synchronous anorectal melanoma and sigmoid adenocarcinoma in an 84-year-old man. The regions of the anorectal melanoma showed melanocytic nevi in the adjacent mucosa of the anal canal and rectum. A dysplastic nevus was also identified in the anal mucosa. This case demonstrates that an anorectal melanoma can arise from pre-existing anorectal melanocytic lesions.

Anorectal malignant melanoma: curative abdominoperineal resection: patient selection with 18F-FDG-PET/CT

Background

Anorectal malignant melanomas (ARMM) are rare tumors, characterized by an early lymphatic spread and distant metastasis, resulting in an extremely poor overall survival. The objective of this study was to determine the pattern of regional lymph node metastasis (LNM) by computed tomography (CT) and 18F-FDG-PET/CT in patients undergoing abdominoperineal resection (APR) and its impact on oncologic outcome.

Methods

A retrospective analysis of six consecutive patients who underwent APR due to primary ARMM was performed. Patients were staged by CT and PET/CT.

Results

Four out of six patients had preoperative LNM involvement (two patients inguinal and perirectal, one iliacal, one perirectal), with two of them presenting with distant metastases additionally. Inguinal/iliacal LNM in two patients as well as liver metastasis in one patient was seen in PET/CT and missed by CT. The three patients with initial inguinal/iliacal LNM died during the observation period (overall survival: 10 (6–18) months). The three patients without inguinal/iliacal LNM involvement are currently alive, one patient showing a slowly progressive disease since 5 years, and two patients are tumor-free since 8.5 and 1.5 years (the patients had initial perirectal LNM).

Conclusions

In ARMM, PET/CT is superior to CT in detection of LNM and distant metastasis. APR is possibly a curative approach if the PET/CT shows exclusively perirectal LNM despite locally advanced tumor growth.

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.

The clinical features and optimal treatment of anorectal malignant melanoma

Anorectal malignant melanoma (AMM) is a very rare and aggressive disease. The purpose of this article is to review the clinical features of AMM, to understand treatment options, and optimal therapy by reviewing pertinent literature. Traditionally an abdominoperineal resection (APR) sacrificing the anal sphincter has been performed for radical resection of cancer, but recently, wide excision of AMM is attempted since quality of life after surgery is an important issue. Some authors reported that there was no difference in five-year survival between the patient who underwent an APR and wide excision. The goal of both APR and wide excision was to improve survival with R0 resection. Adjuvant chemoradiation therapy can be performed to achieve an R0 resection. AMM shows very poor prognosis. At this time, research on AMM is insufficient to suggest a treatment guideline. Thus, treatment options, and a therapeutic method should be selected carefully.

Update on primary mucosal melanoma

Mucosal melanomas are aggressive cancers of mucosal surfaces with clinical and pathologic characteristics distinct from cutaneous melanomas, warranting different staging systems and treatment approaches. Surgical resection is performed frequently for the primary tumor, although the utility of lymph node surgery and radiation therapy is not established. Therapies targeted against C-KIT activating mutations, identified in many mucosal melanomas, are emerging as promising treatments.

Characteristics and survival of korean anal cancer from the Korea central cancer registry data

Purpose

In Korea, anal cancer is rare disease entity with specific clinical characteristics. Therefore, no survival analysis with a sufficient patient population has been performed. The aim of this study was to evaluate the characteristics of Korean anal cancer, focusing on the survival according to tumor histologies, sex, and a specific age group, using the nationwide cancer registry.

Methods

Using the Korea Central Cancer Registry, we analyzed a total of 2,552 cases from 1993 to 2010. We assessed the 5-year relative survival by using tumor histology. In addition, survival differences of Surveillance Epidemiology and End Results (SEER) stage were analyzed for both sexes and for young-age cancer (younger than 40 years) and advanced-age cancer (older than 70 years).

Results

The 5-year relative survival among anal cancer patients increased from 38.9% for the period 1993-1995 to 65.6% for the period 2006-2010. The anal squamous cell carcinoma was the most common histology and showed better survival than other types of cancer. Females demonstrated better survival than males in all SEER stages. The 5-year survivals for patients in whom anal cancer developed before the age of 40 and at or after the age of 40 were 62.4% and 51.6%, respectively. The 5-year survival for patients in whom cancer developed at or after the age of 70 was much worse than that for patients in whom the cancer had developed prior to that age.

Conclusion

Korean anal cancer has certain distinctive characteristics of survival according to tumor histology, sex, and age. Despite limitations on available data, this study used the nationwide database to provide important information on the survival of Korean patients with anal cancer.

Primary anorectal melanoma: an update

The anorectum is a rare anatomic location for primary melanoma. Mucosal melanoma is a distinct biological and clinical entity from the more common cutaneous melanoma. It portrays worse prognosis than cutaneous melanoma, with distant metastases being the overwhelming cause of morbidity and mortality. Surgery is the treatment of choice, but significant controversy exists over the extent of surgical resection. We present an update on the state of the art of anorectal mucosal melanoma. To illustrate the multimodality approach to anorectal melanoma, we present a typical patient.

Primary mucosal melanomas: a comprehensive review

Primary mucosal melanomas arise from melanocytes located in mucosal membranes lining respiratory, gastrointestinal and urogenital tract. Although a majority of mucosal melanomas originate from the mucosa of the nasal cavity and accessory sinuses, oral cavity, anorectum, vulva and vagina, they can arise in almost any part of mucosal membranes. Most of mucosal melanomas occur in occult sites, which together with the lack of early and specific signs contribute to late diagnosis, and poor prognosis. Because of their rareness the knowledge about their pathogenesis and risk factors is insufficient, and also there are not well established protocols for staging and treatment of mucosal melanomas. Surgery is the mainstay of treatment, with trends toward more conservative treatment since radical surgery did not show an advantage for survival. Radiotherapy can provide better local control in some locations, but did not show improvement in survival. There is no effective systemic therapy for these aggressive tumors. Compared with cutaneous and ocular melanoma, mucosal melanomas have lowest percent of five-year survival. Recently revealed molecular changes underlying mucosal melanomas offer new hope for development of more effective systemic therapy for mucosal melanomas. Herein we presented a comprehensive review of various locations of primary melanoma along mucosal membranes, their epidemiological and clinical features, and treatment options. We also gave a short comparison of some characteristics of cutaneous and mucosal melanomas.