Malignant melanoma of the anorectal region

Surgical Management of Primary Anorectal Melanoma: Is Less More?

PURPOSE

Ano-uro-genital (AUG) Mucosal Melanoma UK guidelines recommended a less radical surgical strategy for anorectal melanoma (ARM) where possible. We report our experience of ARM consistent with that approach including clinical presentation, intervention undertaken and prognosis.

METHODS

We present a retrospective study of 15 consecutive patients with ARM surgically treated between November 2014 and April 2023. Patients were divided into the two surgery types: wide local excision (WLE, n = 9) and abdominoperineal resection (APR, n = 6). Data on demographics, diagnosis, treatment and oncological outcomes were assessed between the groups.

RESULTS

The mean age was 65.3 ± 17.4 years and 6 (40.0%) were female patients. Nine patients (60.0%) were diagnosed with stage I and six patients (40.0%) with stage II disease. R0 margins were achieved in all cases. The overall mean length of stay was lower following WLE compared to APR (2.6 ± 2.4 days versus 14.0 ± 9.8 days, p = 0.032). Two complications were observed in the WLE group compared to four complications after APR (p = 0.605). Five patients (55.5%) developed local/distant recurrence in the WLE group compared to three patients (50.0%) in the APR group (p = 0.707), with a median overall survival of 38.5 (12-83) months versus 26.5 (14-48) months, respectively.

CONCLUSIONS

Achieving clear margins by the least radical fashion may have equivalent oncological outcomes to radical surgery, potentially reducing patient morbidity and preserving function. In our experience, the surgical management of ARM consistent with the 'less is more' approach adhering to AUG guidelines has acceptable outcomes.

Anorectal mucosal melanoma

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

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.

Clinical and oncological outcomes of surgery in Anorectal melanoma in Asian population: A 15 year analysis at a tertiary cancer institute

INTRODUCTION

Anorectal malignant melanoma (ARMM) is an aggressive malignancy with dismal prognosis and a 5-year survival rate less than 20% in most of the previous studies. The ideal surgical treatment has still remained controversial. This retrospective study aims at analysing the outcome in patients with ARMM treated with curative surgical resection.

PATIENTS AND METHODS

This is a retrospective study of 38 patients of stage I anorectal malignant melanoma treated with curative surgical resection at our tertiary cancer institute.

RESULTS

WLE (Wide Local Excision) was carried out in 12 patients and APR (abdominoperineal resection) was done in 26 patients. The median overall survival of the entire group in this study was 20 months. Although the median overall survival of WLE patients was higher than those with APR (37 months versus 16 months, respectively), this was not a statistically significant event (P=0.317). The 1-, 2-, 3-, 5-year survival rates were similar with both APR and WLE with no significant difference in the 5-year survival rate (P=0.816); overall 5-year survival rate of just 13%. There were 3 long-term survivors in this study group who survived for more than 10 years.

CONCLUSION

Most patients ultimately succumb to the disease regardless of the management. Both APR and WLE have significant roles in the management depending on the subset of patients selected. Local treatment should be preferred wherever possible. Abdominoperineal resection should be offered in nodal disease or in a recurrent setting.

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.

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.

[Anorectal malignant melanoma : Treatment recommendations]

BACKGROUND

Anorectal malignant melanoma is a rare tumor with a poor prognosis. Typical symptoms (bleeding, pain, perianal mass) are characteristic of hemorrhoids. This, together with the high rate of amelanotic tumors, often delays diagnosis. No therapy guidelines exist.

MATERIALS AND METHODS

Based on our own experience of surgically treated patients and an extensive literature search, we present a stage-dependent therapeutic concept.

RESULTS

Eight patients (six women) with a mean age of 65 ± 8 years were treated at our institution. Six underwent abdominoperineal resection; two had local excision. Two patients additionally underwent inguinal lymph node dissection. Median survival was 12 months with a disease-free survival of 6 months. Forty treatment studies with a total of 1,970 cases could be identified. Prognostic factors are age, time to correct diagnosis, tumor extent, tumor stage, and perineural invasion. The impact of lymph node metastases and R0 resection varies. Surgery is the only effective therapy. Local excision is sufficient when free resection margins are achieved.

CONCLUSIONS

Locally limited tumors should be resected; if possible using local excision. Larger tumors or tumors with sphincter infiltration often require abdominoperineal resection with curative intent. When regional lymph node metastases are present, we advise regional lymphadenectomy of the affected area. In the case of distant metastases, palliative surgery is needed for metastasectomy and in cases of incontinence or refractory pain.

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.

Primary anorectal malignant melanoma treated with neoadjuvant chemoradiotherapy and sphincter-sparing surgery: A case report

Primary anorectal (PA) malignant melanoma (MM) is a rare disease associated with a high mortality rate. The most appropriate treatment strategy for PAMM remains controversial. A 55-year-old female patient, who was misdiagnosed with locally advanced rectal carcinoma, was treated with preoperative radiotherapy and concurrent oral capecitabine. During the therapy, grade 1 leukopenia occurred, however, there was no interruption to treatment. Following chemoradiotherapy, a computer tomography scan identified that the tumor had shrunk significantly and the original enlarged lymph nodes had disappeared. Eight weeks after completion of chemoradiotherapy, sphincter-sparing surgery was performed on the patient and based on the postoperative pathological result, MM was diagnosed. At the time of writing, the patient has survived disease-free for 15 months and at the most recent follow-up examination the Karnofsky Performance Scale score was 100. The therapeutic regimen of neoadjuvant concurrent chemoradiotherapy together with sphincter-sparing surgery is considered to be an optimal choice for patients with PAMM. However, further studies are required to evaluate the efficacy and clinical utility of this therapeutic regimen.

Surgical and radiation therapy management of recurrent anal melanoma

BACKGROUND

Melanoma of the anorectal mucosa is a rare but highly aggressive tumor. Its presenting symptoms are frequently confused with hemorrhoids, thereby causing a delay in diagnosis. Anorectal melanoma carries with it a very poor prognosis. There is a paucity of data investigating management options for anorectal melanoma, and even fewer data reporting recurrent or refractory cases.

CASE PRESENTATION

This case documents a 41-year-old female with a long history of hemorrhoids presenting with anorectal discharge. She was incidentally found have anorectal melanoma following surgical resection. Systemic diagnostic work-up demonstrated PET-avid lymphadenopathy in her right groin. She underwent right groin dissection. However, seven months later she recurred in her right groin and a new recurrent mass was found in her pelvis. She underwent a second groin dissection and resection of the pelvic recurrence. This was followed by a course of hypofractionated radiation therapy then systemic immunotherapy.

DISCUSSION

Surgery has been the mainstay of treatment. However, the extent of surgery has been the topic of investigation. Historically, radical resections have been performed but they result in high rates of post-operative morbidity. Newer studies have compared radical resection with wide local excisions and found comparable outcomes. Anorectal melanoma is frequently a systemic disease. The ideal systemic therapy regimen has not yet been determined but numerous studies show a benefit to multi-agent treatments. Radiation therapy is typically given in the post-operative or palliative setting.

CONCLUSIONS

Anorectal mucosal melanoma is a very rare but aggressive disease with a poor prognosis. The overall treatment goal should strive to optimize quality of life and tumor control while minimizing treatment-related morbidities.

Primary malignant melanoma of the rectum: report of two cases

We report two cases of rectal malignant melanomas. The patients were an 84-year-old male and a 66-year-old female who had blood in their stools. They were preoperatively diagnosed with poorly differentiated adenocarcinoma of the rectum. The clinical diagnosis for each was rectal carcinoma at stage IIIc according to the tumor-node-metastasis classification (6th edition), and the patients underwent abdominoperineal resection with dissection of lymph nodes. Pathological examination of the resected specimens revealed a malignant melanoma. Immunohistochemical analysis results were positive for HMB-45 and negative for cytokeratin AE1/AE3, CD45, and synaptophysin. Primary anorectal melanoma is an uncommon and aggressive disease that carries a poor prognosis. Therefore, it is necessary to provide systemic treatment. To improve prognosis, it is important to detect anorectal melanoma at an early stage.

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.

Primary malignant melanoma of the vagina

OBJECTIVE

To describe the clinical and pathologic features of vaginal melanoma and to determine predictors of outcome in patients with this disease.

METHODS

Thirty-seven women with clinical and radiographic stage I vaginal melanoma treated at one institution between 1980 and 2009 were included in this retrospective study. Treatment modalities were assigned to one of three categories: pelvic exenteration, wide excision, and nonsurgical (primary radiation therapy, chemotherapy, or both). Overall survival and progression-free survival were calculated from the date of the surgical diagnosis.

RESULTS

The median age was 60.6 years. Eighty-four percent of patients were white. Vaginal bleeding was the most common presenting symptom. Lesions were located in the distal third of the vagina in the majority (65%) of patients. Initial management included a wide local or radical excision (76% of patients); pelvic exenteration (14%); and radiotherapy, chemotherapy, or radiotherapy and chemotherapy (10%). At a median follow-up of 17.4 months, 33 women experienced disease recurrence. Recurrence was local only in seven patients (22%), distant only in 20 (63%), and both in five (15%). The most common sites of distant recurrence were lungs and liver. Median progression-free survival was 11.4 months, and median overall survival was 19 months. The 5-year progression-free and overall survival rates were 9.5% and 20.0%, respectively. Patients treated surgically had significantly longer survival than those treated nonsurgically (P=.01). Radiotherapy after wide excision reduced local recurrence risk and increased survival from 16.1 months to 29.4 months, although the increase was not significant (P=.46).

CONCLUSION

Malignant vaginal melanoma, even when localized at presentation, has a very poor prognosis. Patients treated surgically have longer survival than those treated nonsurgically. Radiotherapy after wide excision reduces local but not distant recurrences.

Abdominoperineal resection or local excision? a survival analysis of anorectal malignant melanoma with surgical management

Patients with anorectal malignant melanoma (AMM) generally have an unfavorable prognosis, and surgical managements are still in controversy. The purpose of this study was to evaluate the surgical treatment for AMM in China and to compare the survival of abdominoperineal resection (APR) and local excision (LE) in patients with AMM. Between 1995 and 2007, 54 patients managed with curative surgical resection for AMM were reviewed, 39 patients underwent APR, and 15 patients underwent LE. Life table was carried out and Kaplan-Meier test was used to compare the effects of these two different surgical procedures in survival. The overall 1-year, 2-year, 3-year, and 5-year survival rates after curative operation were 80, 54, 43, and 26%, respectively; LE group were 67, 48, 48, and 16%, and APR group were 84, 57, 42, and 30%, respectively. The median survival for all LE and APR were 25 months, 13 months, and 25 months, respectively. Kaplan-Meier test showed that there was no significant difference between APR and LE in survival (P=0.281); however, a 5-year survival advantage for the patients who underwent APR was found, despite the severity of tumor. Local recurrence after LE was more popular than APR (P=0.020). The prognosis of AMM after curative surgery is poor now, and patients undergoing APR have no significant survival advantage than those underwent LE. Local recurrence after LE was more popular than APR.

Anal melanoma

Anal melanoma is rare and aggressive malignancy. Patients commonly present with advanced, even metastatic disease. Unlike cutaneous melanoma, anal melanoma has no known risk factors. Surgical excision remains the cornerstone of therapy. There are no long-term survivors of stage II or III disease; therefore, early diagnosis and treatment remain crucial. There are no trials definitively proving abdominal perineal resection (APR) or wide local excision (WLE) to yield superior long-term survival. APR may offer a higher rate of local control, whereas WLE offers a much less morbid operation. Adjuvant chemotherapy, interferon, and radiation may offer some benefit.

Effect of misdiagnosis on the prognosis of anorectal malignant melanoma

OBJECTIVE

Anorectal malignant melanoma (AMM) is frequently subjected to misdiagnosis. Here the effect of misdiagnosis on the prognosis of AMM was investigated.

METHODS

Between 1995 and 2007, 79 patients managed for AMM were reviewed; 46 (58.23%) of them had been misdiagnosed during the symptoms, while 33 (41.77%) cases had been diagnosed exactly not more than 1 week after the first visit. Diseases misdiagnosed were categorized as cancer, hemorrhoids, polyps and other diseases. Data were statistically analyzed by using the life tables and Kaplan-Meier curves. The software used was SPSS 16.0 for Windows.

RESULTS

The 1-, 2-, 3- and 5-year survival rates of AMM patients were 58, 33, 24 and 16%, respectively, and the median survival time was 14.0 months; 1-, 2-, 3- and 5-year survival rates of the misdiagnosed patients were 61, 22, 22 and 11%, respectively, and the median survival time was 14.0 months; 1-, 2-, 3- and 5-year survival rates of the patients not misdiagnosed were 55, 44, 25 and 25%, respectively, and the median survival time was 12.0 months. Analyses based on Kaplan-Meier curves revealed no significant effect of misdiagnosis on the survival of AMM patients (P > 0.05). Nevertheless, the diseases misdiagnosed significantly affect the prognosis (P = 0.009); AMM misdiagnosed as hemorrhoids had a poor prognosis, with a 1-year survival rate of only 29% and the median survival of only 6.0 months.

CONCLUSIONS

The misdiagnosed patients had relatively poor prognosis, but the effect of misdiagnosis on the prognosis was not significant; however, misdiagnosis of AMM as hemorrhoids seriously affected the prognosis.

Surgical treatment for anorectal malignant melanoma: report of five cases and review of 79 Japanese cases

INTRODUCTION

Anorectal malignant melanoma (AMM) is a relatively rare disease. Because of its poor prognosis, the optimal surgical treatment for AMM is still controversial and difficult to determine. In this paper, we report five cases of AMM that have been treated by surgery and/or other methods at Shinshu University Hospital within the last decade. We also review the present five cases along with 74 other Japanese cases reported between 1997 and 2006 and discuss the role of surgery in the treatment of AMM.

RESULTS AND DISCUSSION

Among our AMM patients, two who underwent radical abdominoperineal resection had long survival, while the other three patients who underwent palliative surgery had a poor outcome. On the total of 79 AMM patients, those who underwent curative surgery had a better outcome than those who underwent palliative surgery (p < 0.0001). Furthermore, the outcome of AMM patients at stages 0 and I was better than that of AMM patients at stages II, III, and IV (p < 0.0001). There was no significant difference in survival between AMM patients with and without adjuvant chemotherapy.

CONCLUSION

In conclusion, AMM patients treated by curative surgery can expect long-term survival, although the usefulness of adjuvant chemotherapy for AMM patients is controversial.

Anorectal amelanotic melanoma

OBJECTIVE

Anorectal melanoma is a rare, highly malignant tumour with a poor 5 year survival of 10%. Most anorectal melanomas have gross and/or histologic pigmentation, however about 30% of anorectal melanomas are amelanotic.

METHOD

We report three cases of amelanotic anorectal melanomas and integrate our data with six case reports of amelanotic malignant melanoma from the literature. Further we compare clinicopathological data and clinical outcome with large series of anorectal melanomas (both, amelanotic and pigmentated).

RESULTS

There were seven females and two males, of median age 62 years (range: 45-75 years). Rectal bleeding was the leading symptom in all cases with a mean duration of 4 months before diagnosis. Eight of nine patients developed distant metastases. Median survival was 14 months (range: 3-60 months). A tumour thickness of < 4 mm was correlated with long-term disease-free survival, whereas tumour thickness of 4 mm or more was correlated with systemic recurrence.

CONCLUSION

Early diagnosis is key for efficient treatment and improved survival rate for patients with this unusual variant of melanoma. There is no difference in terms of age, time of diagnosis, stage and survival between pigmented and amelanotic anorectal melanoma.

Anal intraepithelial neoplasia and other neoplastic precursor lesions of the anal canal and perianal region

Anal cancer is rare and this helps to explain why anal pre-neoplastic conditions are poorly understood, especially with regard to their natural history and management. Anal intraepithelial neoplasia is closely linked to human papillomavirus infection and is particularly common in homosexuals and in immunosuppressed patients, especially those with HIV/AIDS. The high regression rates of low-grade anal intraepithelial neoplasia may simply reflect inconsistent pathologic reporting. Higher grades of anal intraepithelial neoplasia may remain static for long periods of time in immunocompetent patients, but those with HIV/AIDS show early and rapid malignant transformation. In general, most anal pre-neoplastic conditions are best diagnosed by biopsy and treated by surgical excision, although local recurrence is a problem. In anal Paget's disease, it is important to ascertain, at the time of diagnosis, whether it is due to a primary in-situ apocrine-type of neoplasia of the anus or if the disease is secondary to an invasive primary carcinoma of the rectum.

Primary anorectal malignant melanoma: two case reports and review of the literature

Anorectal melanoma is a very rare tumor with poor prognosis because of delay in diagnosis. It is often mistaken for benign conditions such as hemorrhoids or rectal polyps. Surgical treatment ranges from local excision to radical abdominoperinal resection. Herein, we report 2 cases of anorectal malignant melanoma and further review the diagnostic and therapeutic approaches in light of the pertinent literature.

Melanoma of the anal canal: a case series

PURPOSE

Anal melanoma is an uncommon and aggressive cancer. Different surgical modalities have been used in managing the disease with no clear evidence to favor one approach over another.

METHODS

The medical records of patients with anal melanoma treated at the H. Lee Moffitt Cancer and Research Institute between 1987 and 2004 were reviewed. Published anal melanoma studies, including more than ten patients with outcome data, also were reviewed.

RESULTS

Twelve patients were identified (8 percent of all cancer of the anal canal). Nine were females with a median age of 67 (range, 27-86) years. Four patients had nodal involvement, and one had bone metastases at the time of diagnosis. Five patients had abdominoperineal resection, and six had local excision. Adjuvant radiation therapy with or without interferon was used. Five of the 11 patients without metastatic disease relapsed or died within the first year of diagnosis (4 had local excision and 1 had abdominoperineal resection). Median time to relapse was 6.5 (range, 4-31) months. The liver was the most common site for relapse. Only one patient treated with local excision followed by interferon was a long survivor (no evidence of recurrence at 54 months).

CONCLUSIONS

Anorectal melanoma is a rare and challenging disease. The preoperative staging influences the treatment schedule. In the absence of strong survival benefit of abdominoperineal resection in managing the nonmetastatic form of the disease, it is reasonable to consider local excision as the initial treatment of choice. Adjuvant radiation therapy is well tolerated and is promising in improving locoregional control.

Factors Affecting Survival in Patients with Anal Melanoma

Anal melanoma is an aggressive tumor with a predilection for early infiltration and distant spread, resulting in poor overall survival. Because anal melanoma is rare, only small case series are reported in the literature, making it difficult to draw conclusions about optimal treatment and outcome. The Surveillance, Epidemiology, and End Results database was used to identify patients with anal melanomas from 1973 to 2001. In addition to demographics, disease extent at presentation, treatment administered, overall survival, and survival by decade of diagnosis were collected. A total of 126 patients with a mean age of 69.2 years was diagnosed with anal melanoma. Sixty-one per cent were female. Median follow-up was 22.5 months. Median survival was 10 months for those with distant disease, 13 months for patients with regional spread, and 34 months for patients with local disease (P = 0.0001). Five-year survival was 32 per cent, 17 per cent, and 0 per cent for patients presenting with local, regional, and distant disease, respectively (P = 0.0001). Neither age at diagnosis, operation performed, nor use of radiation significantly affected survival. Anal melanoma remains an uncommon but lethal disease. Extent of disease correlates with overall survival. Survival is improving, but the use and extent of operation are not associated with improved overall survival.

Wide local excision or abdominoperineal resection as the initial treatment for anorectal melanoma?

BACKGROUND

Anorectal melanoma (AM) is a rare tumor with a poor prognosis. Treatment with abdominoperineal resection (APR) over wide local excision (WLE) is still debated. This study aimed to compare median survival of WLE and APR in patients with AM.

METHODS

A systematic review of the literature was performed. Only series that allowed calculation of median survival were included.

RESULTS

Fourteen studies met inclusion criteria. Average median survival of stage I WLE patients (N=34) and stage I APR patients (N=31) was 44 and 22 months, respectively (P=.001). For stage II patients, 7 underwent WLE, and 10 underwent APR with an average median survival of 36 and 14 months, respectively (P=.19).

CONCLUSIONS

This study identified no stage-specific survival advantage to APR in favor of AM. Given that WLE is a more limited intervention associated with at least comparable survival, we propose that it be considered the initial treatment of choice for AM.

A comparison of wide local excision with abdominoperineal resection in anorectal melanoma

Anorectal melanoma is a rare condition and its surgical management is controversial. Seventeen large case series from over the past 10 years were reviewed. The survival of patients treated by either abdominoperineal resection (APR) or wide local excision (WLE) was analysed according to the stage of the disease. Comparison of the survival of patients who underwent APR with those who underwent WLE showed no statistically significant advantage for either procedure in patients at all disease stages. APR should therefore only be performed when local excision is not possible or for palliative purposes.

Biochemotherapy in patients with metastatic anorectal mucosal melanoma

BACKGROUND

Patients with metastatic anorectal melanoma generally have an unfavorable prognosis, but no effective systemic therapy has been reported.

METHODS

The authors retrospectively evaluated the medical records of all patients with metastatic anorectal melanoma treated with biochemotherapy between January 1991 and December 2001 at the University of Texas M. D. Anderson Cancer Center (Houston, TX).

RESULTS

The search yielded 18 patients. Of these patients, 14 had undergone treatment with cisplatin (CDDP), vinblastine (VB), dacarbazine (DTIC), interferon alpha-2b (IFN), and interleukin 2 (IL-2); 2 had undergone treatment with CDDP, VB, DTIC, and IFN; 1 had undergone treatment with CDDP, IFN, and IL-2; and 1 had undergone treatment with CDDP, VB, temozolomide, IFN, and IL-2. All IL-2 treatments were administered intravenously. The median follow-up time was 12.2 months (range, 3.5-43.7 months). Eight patients (44%) had major responses, including two (11%) complete responses (CRs). Three patients were lost to follow-up evaluation after the completion of treatment. The median time to progression among the 15 remaining patients was 6.2 months. Four patients, including 1 with a CR, were alive at their last documented follow-up visits (survival: 14.0, 20.7, 31.3, and 43.7 months, respectively). The median overall survival was 12.2 months. Among 13 patients who received biochemotherapy as first-line systemic therapy, 6 patients (46%) had major responses, including two (15%) CRs. The median time to progression for this group was 6.2 months, and the median overall survival was 12.9 months.

CONCLUSIONS

Biochemotherapy had substantial activity against metastatic anorectal melanoma and should be considered for use in the treatment of metastatic disease from primary anorectal melanoma.

Uncommon anal neoplasms

The neoplasms of the anus discussed in this article are uncommon, and therefore lack a consistent diagnostic and treatment algorithm derived from prospective clinical trial datasets. There may be an opportunity to design prospective Phase II clinical trials, with established uniform surgical pathology, surgical technique guidelines, and endpoints. The American College of Surgeons Oncology Group may have an opportunity to design and carry out controlled clinical trials for select rare anal neoplasms. Such an effort may yield modern benchmarks with which to base subsequent patient care algorithms.

Radiation therapy for malignant melanoma

Although surgery remains the primary treatment for patients with localized melanoma, available data indicate that there is a need for improved local-regional control in situations where complete surgical resection may be difficult or when high-risk features are noted pathologically. Retrospective and phase II prospective studies have revealed that elective/adjuvant radiotherapy can significantly improve the local-regional control rate in these clinical settings. The impact of elective/adjuvant radiotherapy on the incidence of distant metastasis and overall survival has yet to be determined, however. Additionally, there remains a role for radiotherapy as a primary treatment alternative for elderly patients with large facial lentigo maligna melanoma. The optimal radiation fractionation schedule remains controversial. The hypofractionated regimen is well tolerated, has resulted in improved local-regional control as compared with historical surgical results, and is convenient for a group of patients in whom survival expectations are low. Significant improvements in outcome will require commensurate improvements in systemic disease control. The importance of local control to reduce local morbidity, however, should not be underestimated, and future research goals should include randomized clinical trials to further define the role of adjuvant irradiation alone or in combination with systemic therapy.

Ki67 antigen and PCNA proliferation markers predict survival in anorectal malignant melanoma

AIMS

To find a possible correlation of Ki67 antigen and proliferating cell nuclear antigen (PCNA) with prognosis in anorectal malignant melanoma.

METHODS AND RESULTS

Thirty patients with anorectal malignant melanoma were studied. The percentage of tumour cells stained for Ki67 and PCNA in paraffin sections was assessed. Mode of treatment (local excision or abdominoperineal resection), depth of tumour invasion, attempt at cure as defined by complete tumour excision and absence of distant metastases at presentation, tumour blood vessel invasion, and tumour necrosis, as well as Ki67 and PCNA, were all correlated with survival. By univariate analysis, PCNA, Ki67, attempt at cure, local excision (and not abdominoperineal resection), and depth of invasion were all significantly associated with longer survival. By multivariate analysis, only PCNA was significantly associated with survival, while Ki67 showed a significant positive correlation with PCNA. With a cut-off point of 40%, patients with lower Ki67 scores showed survival advantage over those with higher Ki67 scores (P=0.0004). With a cut-off point of 80%, patients with lower PCNA scores showed survival advantage over those with higher PCNA scores (P=0.0001). The staining for proliferation markers was also associated with depth of tumour invasion.

CONCLUSIONS

Ki67 and PCNA immunostaining in paraffin sections may be useful for the prediction of survival in patients with anorectal malignant melanoma. Larger studies are needed to confirm our results.

Sphincter-sparing local excision and adjuvant radiation for anal-rectal melanoma

PURPOSE

To evaluate the outcome and toxicity of a sphincter-sparing treatment strategy in the management of patients with anal-rectal melanoma.

PATIENTS AND METHODS

Between 1989 and 2000, 23 patients with invasive anal-rectal melanoma were managed with sphincter-sparing surgical resection and adjuvant radiation. Surgery consisted of primary local excision, as well as dissection for patients with documented regional nodal disease. Adjuvant radiation was delivered using a hypofractionated regimen of 30 Gy in five fractions over 2.5 weeks. Adjuvant systemic therapy was delivered to nine patients: cytotoxic chemotherapy in seven and immunotherapy in two.

RESULTS

After a median follow-up of 32 months, 15 patients had relapsed and 15 patients had died. The actuarial 5-year overall, disease-specific, disease-free, and distant metastasis-free survival rates were 31%, 36%, 37%, and 35%, respectively. The actuarial 5-year local and regional nodal control rates were 74% and 84%, respectively. No patient had locoregional failure as the sole site of failure and no patient required salvage abdominoperineal resection (APR). By univariate analysis, patients with nodal disease at presentation had a decreased actuarial 5-year disease-specific (0% v 45%, P =.004), disease-free (0% v 45%, P <.001), and distant metastasis-free survival (0% v 42%, P <.001). The actuarial complication-free survival rate was 71%. Two patients developed mild scrotal edema (grade 1), and four patients developed moderate proctitis requiring prolonged medical management (grade 2).

CONCLUSION

Sphincter-sparing local excision and adjuvant radiation is well tolerated and can effectively control local-regional disease while avoiding the functional morbidity of APR.

Long-term survivor of anorectal melanoma: report of a case

Anorectal melanoma is a rare malignant tumor with approximately 500 cases reported in the literature and has dismal long-term survival prospects. Its poor prognosis is attributable to a delay in diagnosis and its inherent biologic aggressiveness, with many patients presenting with metastatic disease. Endoluminal ultrasound is an established mode of evaluation. The mainstay of treatment is usually surgical with curative or palliative intent. The choice of abdominoperineal resection wide local excision of the tumor is controversial. This is an interesting report of a 76-year-old female who presented with an anal mass, eventually underwent a wide local excision of the lesion, which pathologically proved to be malignant melanoma, and was doing well without any evidence of disease ten years after surgery. This is the only known case in the literature of a lesion of this thickness to be "cured" by wide local excision.

Anorectal malignant melanoma: report of a case

A 74-year-old woman presented with anal bleeding and a protuberant mass. A biopsy of the mass revealed the proliferation of spindle-shaped cells with melanin pigments, and an abdominoperineal resection was performed, the histology of which confirmed malignant melanoma. Surgery was absolutely noncurative because massive metastases were encountered in the pelvic and paraaortic lymph nodes. However, postoperative chemotherapy, composed of decarbazine (DTIC), vincristine (VCR), and nimustine hydrochloride (ACNU), achieved satisfactory results. The patient has been well without any evidence of recurrence for more than 3 years.

Anorectal malignant melanoma. A clinicopathologic study, including immunohistochemistry and DNA flow cytometry

BACKGROUND

Anorectal malignant melanoma is a rare tumor with an extremely poor prognosis. DNA flow cytometric study as well as detailed immunohistochemical study have not been reported previously.

METHODS

Eighteen cases of anorectal melanoma were studied, including immunohistology for melanoma markers and epithelial markers and DNA flow cytometric study of paraffin blocks.

RESULTS

Most patients were Ashkenazi Jews, compared with Sephardi Jews and Arabs. Of the 17 patients followed, 14 died of disease at 4-39 months from presentation. Three patients were alive with disease at 12, 53, and 72 months of follow-up. Tumor thickness ranged from 3-35 mm (mean, 12.8 mm). The 2 long term survivors had tumor thickness < or = 7 mm. No correlation was found between the mode of primary surgical treatment (8 patients: abdominoperineal resection; 10 patients: local excision) and outcome. Vimentin, HMB-45, and S-100 protein stainings were positive in 18, 17, and 15 tumors, respectively. Polyclonal carcinoembryonic antigen (CEA), broad-spectrum cytokeratin, epithelial membrane antigen, monoclonal CEA, and TAG-72 (B72.3) stainings were positive in 13, 3 (only focal and rare staining), 2, 0, and 0 tumors, respectively. Thirteen tumors had adequate material for DNA analysis, and all were DNA aneuploid. S-phase fraction could be assessed in 11 tumors and ranged from 7.7-24% (mean, 14%). An S-phase fraction of < 10% was observed in the 2 long term survivors.

CONCLUSIONS

Anorectal melanoma in this study carried a grave prognosis. The frequent staining for polyclonal CEA (with negative monoclonal CEA staining) was probably due to nonspecific cross-reacting antigens. The occasional staining for epithelial markers warrants a comprehensive immunohistochemical study to ensure a correct diagnosis, especially in small biopsies of amelanotic undifferentiated tumors that lack junctional changes. The aneuploidy of all tested tumors reflected their highly malignant behavior. A trend toward longer survival was observed in patients with thin tumors and an S-phase fraction of < 10%. However, due to the small number of survivors, the latter observation should be further tested in a larger scale series.

Surgical treatment of malignant melanoma

The surgical treatment of the primary melanoma site has been made more rational through correlations of rates of local control with various margins of resection in the context of the dominant prognostic indicator for localized melanoma, the thickness of the primary lesion. It is now known that for lesions less than 1 mm in thickness, a 1-cm margin is satisfactory. For lesions 1 to 4 mm thick, a 2-cm margin is adequate according to the results of a multi-institutional, randomized, surgical trial. Lesions thicker than 4 mm should be treated with a margin larger than 2 cm where the anatomy permits, although the main concern for these lesions is their high propensity for distant dissemination. Elective dissection has not been shown to alter survival significantly in prospective randomized trials. Surgical treatment of distant metastases is indicated for the palliation of a symptomatic lesion, for example, solitary brain metastasis or gastrointestinal metastases.

Anorectal malignant melanoma

BACKGROUND

Great controversy exists with regard to the best surgical therapy for anorectal malignant melanoma.

MATERIALS AND METHODS

Between 1980 and 1996, 15 patients with anorectal malignant melanoma were treated. The recurrence pattern after therapeutic intervention and their survival were evaluated.

RESULTS

There were nine females and six males, their mean age was 66.3 years. At diagnosis their disease stages were: I (n=7), 11 (n=3) and III (n=5). Patients with stage I disease were treated with abdominoperineal resection (APR) (n=6) and local excision (n=1); their average tumour size and thickness were: 4.7 cm and 6.4 mm respectively; their median follow-up and disease-free survival were 11 months and 7 months respectively; their recurrence pattern was: local (n=6), inguinal (n=4) and distant (n=6). Those patients with stage II and III disease were treated with transverse colostomy (n=6); two of them received 50 Gy of radiotherapy and local excision plus interferon alpha-2b (n=2), all had progressive distant disease. Patients with stage I disease had a median survival of 12 months compared with 5 months for those with stages II and III (P=0.10). The overall 5-year survival was 0%.

CONCLUSION

The recurrence pattern in anorectal malignant melanoma is mainly at distant sites. The role of APR in maintaining local control over tumours larger than 4 cm or thicker than 5 mm remains elusive.