Anorectal melanoma--an incurable disease?

Primary anorectal malignant melanoma treated with endoscopic mucosal resection

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

Primary rectal melanoma - a case report

The most common site for malignant melanoma is skin, then eye and third is anorectal region. Primary anorectal malignant melanoma is still very uncommon. It is usually very aggressive and presents with altered bowel habit and rectal bleeding. Proctoscopy shows non-pigmented or lightly pigmented polypoid lesion. Histopathology is confirmatory. Early radical excision is mandatory. A 56 year-old female was presented with malignant melanoma of the lower third of rectum. We report this case for its rarity.

Rare presentations of primary melanoma and special populations: a systematic review

A subset of patients with melanoma present in rare and unique clinical circumstances requiring specific considerations with respect to diagnostic and therapeutic interventions. Herein, we present our review of patients with: (1) primary mucosal melanoma of the head and neck, gastrointestinal, and genitourinary tracts; (2) primary melanoma of the eye; (3) desmoplastic melanoma; (4) subungual melanoma; (5) melanoma in special populations: children, nonwhites, as well as a discussion of familial melanoma.

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.

A pilot study of extralevator abdominoperineal excision for primary melanoma of the anorectum

Melanoma of the anorectum represents <2 % of all anorectal cancers and 0.3 % of all primary melanomas. Prognosis is poor, and optimal surgical management is controversial. This series details the surgical management of patients with anorectal melanoma presenting between 2002 and 2013 to the Queen Elizabeth Hospital in Birmingham, UK, a tertiary referral centre for colorectal disease. A retrospective review of patient notes, histology reports, and clinical letters was used to assess perioperative course and long-term outcome of all surgical methods. Eight patients with a median age of 65.5 presented with primary anorectal melanoma during the study period. Six cases were staged as T4 pre-operatively, with two referred as incompletely excised polyps. All eight patients underwent abdominoperineal excision of the rectum (APER), with the most recent four cases undergoing extralevator APER. Clear resection margins were achieved in three out of the four patients in the extralevator APER group with no nodal spread detected at histological assessment. Extralevator APER appears to be feasible and safe in the treatment of melanoma of the anorectum, with 75 % medium-term survival (median 38 months) in selected patients. As it is known that clear margins at surgery are associated with disease-free survival, the wider excision margin at the level of the pelvic floor offered by extralevator APER could result in more favourable surgical outcomes in this prognostically poor malignancy.

Primary anorectal melanoma

Primary malignant melanoma of the anus and rectum is a rare and aggressive neoplasm that tends to invade locally and metastasize early in the course of the disease. It is often misdiagnosed as hemorrhoids or as one of the other benign anorectal conditions and is thus linked to an overall poor prognosis and a 5-year survival rate of less than 20%. Optimal treatment is still controversial, and current evidence does not show any preferential survival benefit from abdominoperineal resection over wide local excision. Chemotherapy or radiotherapy may be used for advanced disease. We report a 71-year-old female presenting with painful bowel movements and blood in stools. She was eventually found to have a mass arising from the anorectal junction with regional lymph node involvement. The patient underwent an abdominoperineal resection and is currently scheduled for chemotherapy.

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 amelanotic melanoma of the rectum mimicking adenocarcinoma

Patient: Male, 55

Final Diagnosis: Melanoma

Symptoms: Worsening constipation • tenesmus • weight loss

Medication: —

Clinical Procedure: Chemoradiation therapy

Specialty: Oncology

Anal versus rectal melanoma: does site of origin predict outcome?

BACKGROUND

Anatomic site is a predictive factor in subtypes of cutaneous and mucosal melanoma.

OBJECTIVE

The aim of this study was to examine the clinical relevance of location of origin of anorectal melanoma as a prognostic factor.

DESIGN

With the use of a prospectively maintained database, clinical characteristics, management, and outcomes were compared according to the site of origin. SETTINGS, PATIENTS, INTERVENTIONS: A retrospective review was conducted of patients diagnosed with anorectal melanoma from 1994 to 2010. Tumors were defined as anal, anorectal, or rectal melanoma according to their anatomic relationship to the dentate line.

MAIN OUTCOME MEASURES

Clinicopathologic factors were compared by χ2 test. Time-to-event analysis was performed by Kaplan-Meier analysis.

RESULTS

Of the 96 patients included (41 with anal melanoma, 32 with anorectal melanoma, 23 with rectal melanoma), patients with rectal and anorectal mucosal melanoma had advanced primary tumors (median Breslow thickness, 12 mm and 8 mm, p = 0.002), whereas anal lesions could be found at earlier depths (median thickness, 6.5 mm). Patients with anal tumors more commonly underwent transanal excision (p < 0.02) and sentinel lymph node biopsy (p = 0.004) versus anorectal and rectal tumors. Patterns of recurrence were also distinct; nearly two-thirds of anorectal and rectal tumors recurred systemically, whereas anal melanoma more often recurred within the lymph nodes first (63%; p < 0.02). Recurrence occurred in 24 (59%) patients with anal tumors, 23 (72%) patients with anorectal tumors, and 16 (70%) patients with rectal tumors. Median overall survival was 22 months for anal melanoma, 28 months for anorectal melanoma, and 27 months for rectal melanoma. Recurrence and survival were not statistically different between the groups.

LIMITATIONS

This study is limited by small sample size and its retrospective nature.

CONCLUSIONS

This study represents the only series describing the outcomes of anorectal melanoma by anatomic location. Lesions at or proximal to the dentate line present with more advanced disease, possibly related to a delay in diagnosis. Lesions distal to the dentate line more commonly recur within lymph nodes, which may represent differences in nodal drainage. Irrespective of location, the long-term prognosis remains poor for all cases of anorectal melanoma.

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.

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.

Anorectal melanoma

Anorectal melanoma is a disease that can be difficult to diagnose because of its unclear presentation. After diagnosis, the main treatment available is surgical resection. Sentinel lymph node mapping has an unclear role in its management. Adjuvant therapy has long been recommended; however, there are no strong data to support its use. Prognostic factors to help gauge survival are also not clear; nevertheless, there is a strong association between stage of disease and histologic perineal invasion. Anorectal melanoma is a very rare disease with a dismal prognosis.

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.

Malignant melanoma arising from a perianal fistula and harbouring a BRAF gene mutation: a case report

Background

Melanoma of the anal region is a very uncommon disease, accounting for only 0.2-0.3% of all melanoma cases. Mutations of the BRAF gene are usually absent in melanomas occurring in this region as well as in other sun-protected regions. The development of a tumour in a longstanding perianal fistula is also extremely rare. More frequent is the case of a tumour presenting as a fistula, that is, the fistula being a consequence of the cancerous process, although we have found only two cases of fistula-generating melanomas reported in the literature.

Case Presentation

Here we report the case of a 38-year-old male who presented with a perianal fistula of four years of evolution. Histopathological examination of the fistulous tract confirmed the presence of malignant melanoma. Due to the small size and the central location of the melanoma inside the fistulous tract, we believe the melanoma reported here developed in the epithelium of the fistula once the latter was already formed. Resected sentinel lymph nodes were negative and the patient, after going through a wide local excision, remains disease-free nine years after diagnosis. DNA obtained from melanoma tissue was analysed by automated direct sequencing and the V600E (T1799A) mutation was detected in exon 15 of the BRAF gene.

Conclusion

Since fistulae experience persistent inflammation, the fact that this melanoma harbours a BRAF mutation strengthens the view that oxidative stress caused by inflammatory processes plays an important role in the genesis of BRAF gene mutations.

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.

Neoplasms of anal canal and perianal skin

Tumors of the anus and perianal skin are rare. Their presentation can vary and often mimics common benign anal pathology, thereby delaying diagnosis and appropriate and timely treatment. The anatomy of this region is complex because it represents the progressive transition from the digestive system to the skin with many different co-existing types of cells and tissues. Squamous cell carcinoma of the anal canal is the most frequent tumor found in the anal and perianal region. Less-frequent lesions include Bowen's and Paget's disease, basal cell carcinoma, melanoma, and adenocarcinoma. This article aims to review the clinical presentation, diagnostic evaluation, and treatment options for neoplasms of the anal canal and perianal skin.

Anorectal malignant melanomas: Retrospective experience with surgical management

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

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

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

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

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.

Treatment and outcomes of anorectal melanoma

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anorectal melanoma

The authors review the epidemiologic, clinicopathologic, and molecular features of anorectal melanoma, and discuss the differences between this uncommon and lethal disease and the more common and curable cutaneous form. Observations regarding outcomes after surgical resection will also be discussed, as well as predictors of survival and the use of adjuvant therapies. The recent discovery that the KIT oncogene may be aberrantly activated in a subset of patients with anorectal melanoma creates a realm of possibility for the development of targeted molecular therapy. Melanoma of the anorectum is an extremely rare tumor that is often difficult to diagnose. Its surgical management is controversial, and the prognosis remains poor.

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.

Mucosal melanomas: a case-based review of the literature

Mucosal melanoma is a rare cancer that is clearly distinct from its cutaneous counterpart in biology, clinical course, and prognosis. Recent studies have shown important differences in the frequencies of various genetic alterations in different subtypes of melanoma. Activating mutations in the c-KIT gene are detected in a significant number of patients with mucosal melanoma. This observation has resulted in the initiation of several clinical trials aimed at exploring the role of receptor tyrosine kinases that inhibit c-KIT in this patient population. We herein present a comprehensive literature review of mucosal melanoma along with case vignettes of a number of pertinent cases. We further discuss melanomas of the head and neck, the female genital tract, and the anorectum, which are the three most common sites of mucosal melanoma, with a particular focus on the diagnostic, prognostic, and therapeutic data available in the literature.

Surgery of primary melanomas

Surgery remains the mainstay of melanoma therapy, regardless of the tumor site. Only the early diagnosis combined with proper surgical therapy currently gives patients affected by this malignancy the chance for a full cure. The main goal of surgical therapy is to provide the local control of the disease and to secure long-term survival of the patient without reasonable functional and esthetic impairment. The recommended method of biopsy—excisional biopsy, as an initial diagnostic and, to some extent, therapeutic procedure—is performed under local anesthesia as an elliptical incision with visual clear margins of 1–3 mm and with some mm of subcutaneous tissue. The extent of radical excision of the primary tumor (or scar after excisional biopsy) is based on the histopathologic characteristics of the primary tumor and usually consists of 1–2 cm margins with primary closure. The philosophy behind conducted randomized clinical trials has been to find the most conservative surgical approach that is able to guarantee the same results as more demolitive treatment. This has been the background of the trials designed to define the correct margins of excision around a primary cutaneous melanoma. Much less definition can be dedicated to the surgical management of patients with non-cutaneous melanomas.

Long-term outcomes after local excision and radical surgery for anal melanoma: data from a population database

PURPOSE

Anal melanoma is rare and associated with a poor outcome. Previous studies that have reported outcomes after surgical treatment are limited by both small number of participants and treatment at single centers only. This study evaluates survival of patients undergoing surgery for anal melanoma from a prospective, population-based database.

METHODS

Characteristics and survival of patients undergoing rectal resection or local excision for anal melanoma of the anus, anal canal, and overlapping region of the rectum from 1982 to 2002 were obtained from the Surveillance, Epidemiology and End Results database and compared.

RESULTS

A total of 160 patients were included in the study. Details of previous surgical procedures were available for 109 of the study patients: 60 (55%) underwent local excision and 49 (45%) rectal resection. Patients who underwent local excision were significantly older (73.5 vs 65.1 years, P < .001), whereas those who had undergone rectal resection had a greater proportion of regional disease (73.5% vs 16.7%, P < .001). The median survival of the 2 groups was similar (rectal resection vs local excision: 17 vs 28 months, P = .3). Rectal resection and local excision were associated with similar survival for patients in both regional (P = .6) and localized (P = .95) stages. Outcomes for patients who were appropriately pathologically staged after rectal resection depended on localized vs regional stage (5-year survival: 43.1% vs 12.5%, P = .17). Survival for patients in localized and regional stages who underwent rectal resection was similar to that for patients with corresponding clinical stage who underwent local excision.

CONCLUSION

Survival of patients with anal melanoma is similar after local excision or rectal resection irrespective of whether patients have localized or regional stage of disease.

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.

Malignant melanoma of the anorectum--a rare entity

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Importance of clear resection margins in anorectal malignant melanoma

BACKGROUND

Anorectal melanoma is rare and surgery is the recommended primary treatment. There has been some debate whether abdominoperineal resection (APR) or local excision is most appropriate. The aim of this study was to provide a population-based analysis of symptoms, treatment and outcome.

METHODS

From the Swedish National Cancer Registry, 251 patients with anorectal melanoma were identified from 1960 to 1999. Medical reports were collected and reviewed retrospectively. R0 resection was defined by clear macroscopic margins and a pathology report showing a margin greater than 10 mm. Survival was compared with the log rank test, and Cox multivariable analysis was performed.

RESULTS

APR and local excision was performed in 66 and 86 patients respectively. Median survival after surgery was 14 months, with no statistically significant difference between the two groups. Seventy-two patients in whom an R0 resection was achieved, irrespective of approach, had a significantly better overall 5-year survival rate than patients with involved margins (19 versus 6 per cent; P < 0.001). Multivariable analysis showed resection status and tumour stage to be independent prognostic variables.

CONCLUSION

Both APR and LE seem appropriate for anorectal melanoma provided clear margins can be achieved; prognosis is poor regardless of surgical approach.

Laparoscopic abdominoperineal resection for anorectal melanoma: a case report and review of the literature

Anal melanoma is a rare colorectal disease, accounting for 4% of all anal malignancies. Here we report the first case of a patient with anorectal melanoma who was treated laparoscopically. He underwent a totally laparoscopic abdominoperineal resection with excellent postoperative recovery. One year postoperatively, he is now clinically recurrence free with a normal colonoscopy. The literature on anorectal melanoma has been reviewed and controversy still surrounds the optimal treatment modality. We propose that a laparoscopic approach to the management of this disease can be considered when deciding future treatment plans for patients with this condition.

Amelanotic Anorectal Malignant Melanoma: Case Report with Immunohistochemical Study and Literature Review

Epithelioid cell tumors presenting in the gastrointestinal tract are uncommon, but when they arise, arriving at a correct diagnosis is important. We report a case of anal malignant melanoma in an 82-year-old man who microscopically showed an epithelioid malignant tumor simulating a gastrointestinal stromal tumor. C-kit stain and Melan-A were diffusely and strongly positive, while HMB-45 was focally positive. This case illustrates the potential pitfall of relying on a single antibody or inadequate panel of immunohistochemical stains to confirm the diagnosis. We recommend to apply an adequate immunohistochemical panel which includes S-100 protein, HMB-45 and Melan-A in order to make an accurate diagnosis, and discuss the differential diagnosis and surgical treatment modalities.

Primary ano-rectal malignant melanomas within a population-based national patient series in Sweden during 40 years

PURPOSE

To analyze 251 patients (101 males and 150 females) diagnosed with ano-rectal malignant melanoma (ARMM) reported to the Swedish National Cancer Registry during 1960-1999.

METHODS

Incidence, gender and age profiles, primary anatomical sites and density of the melanomas along with geographic distribution, and prognosis were investigated.

RESULTS

The age-standardized incidence of ARMM was significantly higher for females (1.0 per 10(6) females) than for males (0.7 per 10(6) males) throughout the 40-year-period. The incidence increased with age peaking at 75-84 years in both genders. 54% of the tumours were primary in the anal canal, 24% engaged the whole ano-rectal unit and 10% were located at the anal verge (11% unknown primary site). Although ARMM were rare in absolute numbers, their density (number of tumours/square unit) was higher than that of cutaneous malignant melanomas (CMM) on average. No linkage between the geographic distribution of ARMM and population density was found. The prognosis was very poor albeit with a significant gender difference with a five-year survival rate of 10.6% for males and 15.7% for females. The survival rates for both genders improved during the 40-year-period but significantly more for females than males.

CONCLUSION

The reason(s) for the difference in incidence and prognosis according to gender is unknown. The majority of ARMM emerged primary in the anal canal and a primary location exclusively in the colonic mucosa of the rectum is questionable. The higher density of ARMM as compared to the average density of CMM tallies with the result of our previous studies on vulvar melanoma and might be instrumental in exploring non-UV light associated factors in melanoma genesis. The concentration of patients with anal squamous cell carcinoma to population-dense urban areas, as previously reported, was not found in cases of ARMM.

Complete response of stage IV anal mucosal melanoma expressing KIT Val560Asp to the multikinase inhibitor sorafenib

BACKGROUND

A 79-year-old man presented to his primary care physician with a 2-month history of pruritus ani and a pigmented nodular lesion was discovered in the posterior rectum. The patient had no other symptoms, or any family history of malignancy.

INVESTIGATIONS

Physical examination; excisional biopsy; CT scan of the chest, abdomen and pelvis; lung biopsy; blood tests; tumor immunohistochemistry for KIT, vascular endothelial growth factor platelet-derived growth factor receptor alpha and beta, and mismatch-repair proteins MLH1, MSH2, and MSH6; and KIT and BRAF tumor genotyping.

DIAGNOSIS

Stage IV M1b metastatic anal mucosal melanoma.

MANAGEMENT

Wide local excision with mucosal advancement of the rectal wall, external-beam radiation, and sorafenib-temozolomide therapy.

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.

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

AIMS

This study describes the experience of the National Cancer Institute of Milano in the treatment of anorectal melanoma over the last 32 years.

METHODS

The influence of different surgical approaches on local care and final outcome was investigated on 40 completely evaluable patients, followed for a median follow-up time of 75 months. The analysis was carried out by calculating and comparing overall survival, disease-free survival and cumulative incidence curves of disease recurrence.

RESULTS

Thirty-one patients underwent radical surgery: nine abdominoperineal resections, four total rectal resections and coloendoanal anastomosis, and 18 local excisions. The remaining nine patients received palliative treatments. Median overall survival time for patients receiving non-radical treatments was poor: only 6 months. However, even when a radical surgery was undergone, the prognosis of patients with anal melanoma remains dismal. Local relapse incidence was 45.8% for the limited surgery group, but non-existent for the extended-surgery group (p = 0.007). However, the median disease-free survival time was 7 and 9 months for patients receiving limited or major surgery (p = 0.97). Overall survival was 17 months, irrespective of the adopted surgery.

CONCLUSION

Prognosis of anal melanoma remains poor. Final outcome is not influenced by modality of surgery. A limited but radical excision can be considered whenever possible while a major demolitive surgery should be applied only for therapy of advanced or bulky lesions.

Melanoma of the rectum: A rare entity

A 41-year-old man presented with a 6-mo history of changed defecation and rectal bleeding. A 3-cm polypoid tumor of the lower rectum was found at rectosigmoidoscopy, which proved to be a leiomyosarcoma upon biopsy. Dissemination studies did not show any metastases. He was underwent to an abdomino-perineal resection (APR). Histopathology of the specimen showed a melanoma (S-100 stain positive). Two years after the resection, metastases in the abdomen and right lung were found. He died one and half years later. Primary anorectal melanoma is a rare and very aggressive disorder. According to current data, one should always perform a S-100 stain when anorectal sarcoma is suspected. A positive S-100 stain suggests the tumour to be most likely a melanoma. Subsequently, thorough dissemination studies need to be performed. Depending on the outcome of the dissemination studies, a surgical resection has to be performed. Nowadays, a sphincter-saving local excision combined with adjuvant loco-regional radiotherapy should be preferred in case of small tumors. The same loco-regional control is achieved with less “loss of function” compared to non-sphincter saving surgery. Only in the case of large and obstructing tumors an abdomino-perineal resection is the treatment of choice.

Multiple bilateral choroidal metastasis from anal melanoma

A 58-year-old Caucasian woman with bleeding per rectum had a melanoma of the anal canal. She subsequently presented with visual disturbance and was noted to have bilateral multiple choroidal metastasis, along with other multiple systemic metastases. Orbital radiotherapy led to near complete resolution of the ocular metastasis.

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.