Anorectal malignant melanoma in Sweden. Report of 49 patients

Amelanotic Malignant Melanoma With Atypical Divergent Neuroendocrine Differentiation: A Report of an Unusual and Rare Case of Anorectal Bleeding

Melanocytes located between the anal transition zone and the dentate line of the anal canal can give rise to the uncommon malignant tumor known as anal melanoma. It has a fast-paced clinical course and can masquerade as several common anorectal symptoms, such as hemorrhoids or rectal ulcers. In melanoma, divergent differentiation is a very uncommon phenomenon. The diagnosis of melanoma is difficult with histopathology sections alone (hematoxylin and eosin, H&E). Special stains and ancillary immunohistochemistry investigations are useful in these situations. A 60-year-old female patient presented to the surgical outpatient department with complaints of anorectal bleeding. After clinical evaluation, a growth in the anorectal region was identified, and a biopsy was taken from the growth. Histopathological and subsequent immunohistochemical analysis of the biopsy material was done at the Department of Pathology. A diagnosis of amelanotic melanoma with atypical and divergent neuroendocrine differentiation involving the anorectal region was rendered. Histologically, this tumor showed extremely pleomorphic polygonal to elongated spindle cells that co-expressed neuroendocrine markers and were positive for S100, HMB-45, and Melan-A. This case presented many diagnostic challenges at both the histomorphological level and the immunohistochemical expression profile analysis. We will go into great depth regarding the diagnostic challenges in this instance and provide an outline of our approach. The immunohistochemical and prognostic importance of this case will also be covered.

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.

Successful Multidisciplinary Treatment with Laparoscopic Hepatectomy and Adjuvant Therapy for Metachronous Solitary Hepatic Metastasis after Excision of a Primary Anorectal Malignant Melanoma: A Case Report

Anorectal malignant melanoma (ARMM) is extremely rare and generally lethal, irrespective of the treatment administered. The disease is often diagnosed late, metastases being present in approximately two-thirds of patients at the time of initial diagnosis. Solitary metastasis of ARMM to a distant organ is exceedingly rare. A 76-year-old woman with a history of laparoscopic abdominoperineal resection of an ARMM 13 months previously, was found to have a solitary liver metastasis in the follow-up computed tomography. A preoperative work-up showed no other distant metastases nor contraindication to surgery. It was therefore considered that resection was indicated. The metachronous solitary liver metastasis from an ARMM was treated by laparoscopic wedge hepatectomy of the eighth segment 18 months after excision of her primary ARMM. Adjuvant therapy with pembrolizumab was initiated and continued at 6-week intervals. The patient has not exhibited any immune related Adverse Effects (irAE) during or subsequent to treatment with pembrolizmab and has now completed 12 months of adjuvant pembrolizumab therapy, having survived 33 months from the initial operation for primary ARMM, and remaining recurrence-free 14 months after hepatectomy. ARMM is extremely rare and resection of a metachronous solitary metastasis followed by adjuvant therapy has not previously been reported. We hope this case will be useful for clinicians who might treat similar patients.

Primary anorectal amelanotic melanoma with liver, lungs and lymph nodal metastases

Anorectal melanoma (ARM) is an exceedingly rare and very aggressive malignancy. It originates from the melanocytic cells in the anorectal mucosa, which produces melanin. Other mucosal melanomas commonly found in the mucosa of the oral cavity, vulvovaginal, pharynx and urinary tract. Patients usually present with bleeding per rectum, perianal pain and difficulty in defaecation. Distinction of primary anorectal melanoma from other tumours of this region is difficult because of the lack of common imaging features. MRI is the modality of choice for its better tissue characterisation and resolution. There is no standard treatment protocol available mainly due to scarcity of data. Surgery is the mainstay therapy. Herein we present a case of a male patient in his 30s who presented with rectal bleeding and perianal pain. Haematological analysis revealed normocytic normochromic anaemia. MRI detected a mass lesion in the anorectal region. Contrast enhanced CT revealed multiple metastases in the liver, lungs, periportal, mesorectal and inguinal lymph nodes. The diagnosis of the ulcerated anorectal melanoma was established on histopathological examination. The patient underwent abdominoperineal resection (APR) followed by chemotherapy. Afterward the patient presented to the emergency room with respiratory distress for which he was on ventilator support. Sadly, the patient died after four days.

Organ preservation in anorectal melanoma: A tempting challenge-a case report

Melanoma arising from melanocytes is an uncommon neoplastic lesion, with rare occurrences in anorectal mucosa. While mucosal melanomas constitute a small portion of all melanomas, anorectal cases are even rarer and present with aggressive behavior and poor prognosis. Surgical management is central, with evolving debates regarding optimal approaches. We present a case of a 60-year-old woman with anorectal melanoma. She complained of rectal bleeding and weight loss. Clinical examination and pelvic magnetic resonance imaging revealed a 3-cm budding lesion on the anterior rectal wall. Colonoscopy identified a pedunculated anorectal tumor of 3 cm, situated 4 cm from the anal margin. A biopsy led us to a malignant lesion: anorectal melanoma. Pelvic imaging displayed a localized tumor, prompting wide local excision with millimetric negative margins. These resection margins were estimated insufficient, even in front of R0 resection. Thus, and after multidisciplinary discussion, we opted for abdominoperineal resection after wide local excision. Lymph nodes were biopsied, confirming no residual tumor. Follow-up exhibited no recurrence at 1 year. Our case emphasizes the pivotal role of surgical strategy in managing anorectal melanoma, challenging the paradigm of organ preservation. Despite therapeutic progress, surgery remains integral, contributing to improved outcomes and addressing the metastatic potential inherent to this disease.

Incidence and survival of patients with primary gastrointestinal melanoma: a population-based study

BACKGROUND

Primary gastrointestinal melanoma (PGIM) has received more attention because of its inferior prognosis. Less is known about the incidence and survival rate of PGIM.

METHODS

PGIM data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The incidence was estimated by age, sex, race, and primary site. Trends in incidence were described as annual percent change (APC). Cancer-specific survival (CSS) and overall survival (OS) rates were estimated and compared using log-rank tests. Cox regression analyses were performed to identify independent prognostic factors.

RESULTS

The overall incidence of PGIM was 0.360/1,000,000 with a significant upward trend (APC = 1.77%; 95% CI 0.89%-2.67%, p < 0.001) from 1975 to 2016. Most PGIM occurred in the large intestine (0.127/1,000,000) and anorectum (0.182/1,000,000), and both incidences were almost 10 times higher than those of other sites, including the esophagus, stomach, and small intestine. The median survival time was 16 months (IQR, 7-47 months) for CSS and 15 months (IQR, 6-37 months) for OS, and the 3-year CSS and OS rates were 29.5% and 25.4%, respectively. Older age, advanced stage, absence of surgery, and melanoma in the stomach were the independent risk indicators of survival and associated with worse CSS and OS.

CONCLUSION

The incidence of PGIM has been increasing over the past decades and the prognosis is poor. Thus, further studies are warranted to improve the survival, and more attention should be paid to the patients that are elderly, patients with advanced stage, and patients with melanoma in the stomach.

Melanoma de Mucosa Oral, Genital e Anorretal

Entre 1970 e 1997, 411 pacientes com diagnóstico de melanoma foram atendidos no Hospital São Judas Tadeu de Barretos. Destes, 7 (1,7%) eram de mucosa e os respectivos prontuários foram analisados para este trabalho. Quanto à localização, eram anorretal; 2 eram vulvovaginal, e 1 localizava-se no palato; havia seis pacientes do sexo feminino e um masculino variando as idades de 31 a 81 anos (média = 61 anos). Apenas um paciente apresentou tumor localizado (está com quase 5 anos de sobrevida), 4 tinham doença regional (todos faleceram antes de 3 anos após o diagnóstico) e dois tinham metástases (óbitos ocorridos antes de um ano após diagnóstico). Os tratamentos variaram de conformidade com o estadiamento da doença. Os dados evidenciam o prognóstico ruim da moléstia, que se apresenta, usualmente em estádios avançados e, freqüentemente, com metástases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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.

Combining quantitative and qualitative magnetic resonance imaging features to differentiate anorectal malignant melanoma from low rectal cancer

Background

Distinguishing anorectal malignant melanoma from low rectal cancer remains challenging because of the overlap of clinical symptoms and imaging findings. We aim to investigate whether combining quantitative and qualitative magnetic resonance imaging (MRI) features could differentiate anorectal malignant melanoma from low rectal cancer.

Methods

Thirty-seven anorectal malignant melanoma and 98 low rectal cancer patients who underwent pre-operative rectal MRI from three hospitals were retrospectively enrolled. All patients were divided into the primary cohort (N = 84) and validation cohort (N = 51). Quantitative image analysis was performed on T1-weighted (T1WI), T2-weighted (T2WI), and contrast-enhanced T1-weighted imaging (CE-T1WI). The subjective qualitative MRI findings were evaluated by two radiologists in consensus. Multivariable analysis was performed using stepwise logistic regression. The discrimination performance was assessed by the area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI).

Results

The skewness derived from T2WI (T2WI-skewness) showed the best discrimination performance among the entire quantitative image features for differentiating anorectal malignant melanoma from low rectal cancer (primary cohort: AUC = 0.852, 95% CI 0.788-0.916; validation cohort: 0.730, 0.645-0.815). Multivariable analysis indicated that T2WI-skewness and the signal intensity of T1WI were independent factors, and incorporating both factors achieved good discrimination performance in two cohorts (primary cohort: AUC = 0.913, 95% CI 0.868-0.958; validation cohort: 0.902, 0.844-0.960).

Conclusions

Incorporating T2WI-skewness and the signal intensity of T1WI achieved good performance for differentiating anorectal malignant melanoma from low rectal cancer. The quantitative image analysis helps improve diagnostic accuracy.

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.

Incidence and Survival Patterns of Rare Anal Canal Neoplasms Using the Surveillance Epidemiology and End Results Registry

Small cell, neuroendocrine tumors, and melanoma of the anus are rare. Limited data exist on the incidence and management for these rare tumors. A large, prospective, population-based database was used to determine incidence and survival patterns of rare anal neoplasms. The Surveillance, Epidemiology and End Results registry was queried to identify patients diagnosed with anal canal neoplasms. Incidence and survival patterns were evaluated with respect to age, sex, race, histology, stage, and therapy. We identified 7078 cases of anal canal neoplasms: melanoma (n = 149), neuroendocrine (n = 61), and small cell neuroendocrine (n = 26). Squamous cell carcinoma (SCC) (n = 6842) served as the comparison group. Anal melanoma (AM) demonstrated the lowest survival rate at 2.5 per cent. Neuroendocrine tumors (NETs) demonstrated similar survival as SCC (10-year survival for regional disease of 25 and 22.3%, respectively). Ten-year survival of small cell NETs resembled AM (5.3 vs 2.5%). Age 60 years or older, sex, black race, stage, and surgery were independent predictors of survival. This study presents the largest patient series of rare anal neoplasms. NETs of the anal canal demonstrate similar survival patterns to SCC, whereas small cell NETs more closely resemble AM. Accurate histologic diagnosis is vital to determine treatment and surgical management because survival patterns can differ among rare anal neoplasms.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSION

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

A rare case of recurrent primary anorectal melanoma emphasizing the importance of postoperative follow-ups

BACKGROUND

Primary anorectal melanoma can be a rare differential diagnosis of anorectal mass. Due to the low case number reported in the literature, physicians are not aware of this aggressive disease. Although no consensus exists, wide local excision and abdominoperineal resection are considered the mainstay therapy.

CASE PRESENTATION

An 85-year-old female patient presented with fecal incontinence 5 years after local resection of a primary anorectal melanoma. In the rectoscopy, a tumor proximal to the dentate line was identified and later confirmed as a recurrent primary anorectal melanoma. There were no signs of locoregional or distant metastasis on the MRI and PET/CT. She underwent another wide local excision and regained fecal continence postoperatively.

CONCLUSIONS

Primary anorectal melanoma should belong to the differential diagnosis of anorectal mass. If technically feasible, wide local excision represents a less invasive treatment than abdominoperineal resection, retaining the anal sphincter and patient's quality of life. Even though wide local excision has a higher recurrence rate than abdominoperineal resection, there is no difference in survival between the two procedures. This is only under the premise that patients are followed-up regularly after wide local excision so that recurrence can be spotted early on and locally excised.

Primary anorectal malignant melanoma: A case report

INTRODUCTION

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

PATIENT CONCERNS

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

DIAGNOSIS

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

INTERVENTIONS

The patient underwent abdominoperineal resection with no other adjuvant therapy.

OUTCOMES

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

CONCLUSION

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

Primary Melanoma: from History to Actual Debates

PURPOSE OF REVIEW

This review describes the long scientific background followed to design guidelines and everyday clinical practice applied to melanoma patients. Surgery is the first option to cure melanoma patients (PTS) at initial diagnosis, since primary cutaneous lesions are usually easily resectable. An excisional biopsy of the lesion, with minimal clear margins, can be obtained in the vast majority of cases. Punch biopsies may be proposed only in case of large lesions located on specific cosmetic or functional areas like the face, extremities, or genitals where a mutilating complete resection would not be performed without prior histological diagnosis.

RECENT FINDINGS

After the histologic confirmation of melanoma, definite surgical excision of the scar and surrounding tissue is planned, to obtain microsatellite free margins. The width of these margins has been identified following the results of several clinical trials and it is either 1 or 2 cm, depending on the Breslow thickness of the primary tumor. Following the latest staging system proposed by the American Joint Cancer commission (AJCC), a sentinel node biopsy (SNB) is usually performed in case of a primary lesion > 0.8 mm thickness or for high-risk thinner lesions, if no evidence of nodal involvement has been identified clinically or radiographically. Surgical management of primary melanoma is well established. There is debate on the optimal surgical margins for 1-2 mm melanomas. There are specific considerations for special primaries (bulky, extremity, mucosal). Sentinel node (SN) evaluation does not improve survival, but is routinely used as staging.

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

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

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

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

Primary Anorectal Malignant Melanoma: Report of two Cases

Primary anorectal malignant melanoma is a fairly uncommon but highly malignant disease. It is sometimes mistaken for benign conditions such as hemorrhoids or rectal polyps. Here we describe two cases of primary malignant melanoma of the rectum: in one patient a wide local excision (WLE) was performed and in the other an abdominoperineal resection (APR), both with curative intent. Both patients developed systemic recurrences and died of their disease at 24 and 10 months, respectively. In conclusion, the prognosis of anorectal melanoma is poor, irrespective of surgical treatment. WLE is the first choice for primary anorectal melanoma, while APR should be reserved for those cases where complete transrectal tumor resection is technically impossible.

Clinical and Imaging Features of Noncutaneous Melanoma

OBJECTIVE

The purpose of this article is to summarize the epidemiologic characteristics, clinical aspects, and radiologic appearance of as well as the management considerations and differential diagnoses for noncutaneous primary melanomas occurring at specific anatomic sites. Primary ocular, sinonasal, meningeal, biliary, adrenal, alimentary tract, and genitourinary melanomas are highlighted.

CONCLUSION

Noncutaneous primary melanomas are a complex group of malignancies with biologic findings that are unique when compared with findings for cutaneous melanomas. Each noncutaneous primary melanoma has its own specific diagnostic and management challenges, depending on the anatomic location where they arise.

Sinonasal Melanoma: A Case Report and Literature Review

Purpose. Sinonasal malignant mucosal melanoma is a rare, aggressive tumour. Nasal obstruction and epistaxis are the most commonly reported symptoms, although symptomatology may develop late and be nonspecific, which tends to delay diagnosis, resulting in a poorer prognosis. Case Report. This report describes a 64-year-old male patient with nasal obstruction and epistaxis. Computed tomography of the facial sinuses revealed a large lesion in the right nasal cavity, with infiltration into the left cavity, ethmoidal cells, and erosion of the cribriform plate. Initial incisional biopsy revealed an undifferentiated carcinoma of the right maxillary sinus, staged as T4aN0M0. Induction chemotherapy was initiated with cisplatin and etoposide. Response to treatment was complete. The patient was then submitted to radiotherapy with concomitant cisplatin. Immunochemical analysis revealed positivity for vimentin, S100, and HMB-45 (human melanoma black 45), a result compatible with a diagnosis of malignant melanoma. Discussion. Due to the rarity of the tumour and the patient's complete response to chemotherapy and since no blackened lesion had been found at the previous exam, treatment was continued as planned. The patient remains healthy, with no metastasis or recurrence. He is currently being monitored by the clinical oncology team.

Diagnostic value of MRI and computed tomography in anorectal malignant melanoma

Here, we report 12 cases of anorectal malignant melanoma (ARMM), which has a very rare incidence. Patients were examined by either computed tomography or MRI or computed tomography combined with MRI before they underwent a remission operation. Because of the paramagnetic contribution from melanin, the short T(1) and short T(2) signals in MRI were specific to melanoma. MRI is reliable in the early diagnosis of ARMM, which is confirmed by pathological reports. Therefore, we advocate the application of a radiological screen using MRI for those patients with a mole in the anorectal region and abnormal colonoscopy findings.

Malignant Melanoma Metastatic to Gastrointestinal Tract

Malignant melanomas metastatic to the gastrointestinal (GI) tract show a wide range of histologic features, many of which can mimic primary GI malignancies. In this study, we evaluated the clinicopathologic features of 41 cases of malignant melanoma involving the GI tract. Thirty-two patients were men and nine were women; the average patient age was 51.7 years (range, 26-74 years). Twenty-eight patients had a history of malignant melanoma. Thirteen patients, however, did not have a prior history of malignant melanoma; on the basis of the clinical presentation and the behav ior of the GI lesions of these cases, they were presumed to be metastases from regressed or clinically undetected melanomas. The small intestine was the most common site. 12 patients had involvement of multiple GI sites. Clinical diagnoses at presentation included GI bleeding of unknown etiology, small bowel obstruction, rectal carcinoma, gastric ulcer, lymphoma, and cholelithiasis. The three major histologic patterns that mimicked primary GI neoplasms were carcinoma-like, carcinoid-like, and stromal sarcoma-like. The average survival times were 61.9 months after the diagnosis of primary melanoma and 14.4 months from the time of GI tract involvement. Site of malignant melanoma in the GI tract, histologic pattern, and history of a primary lesion outside GI tract did not show any prognostic significance. Although metastatic malig nant melanomas of the GI tract are rare, they should be considered in the differential diagnosis of primary GI tumors. Int J Surg Pathol 2(1):3-10, 1994

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.

Preliminary Suggestion about Staging of Anorectal Malignant Melanoma May Be Used to Predict Prognosis

PURPOSE

Anorectal malignant melanomas (AMM) are rare and have poor survival. The study aims to evaluate the clinicopathologic characteristics and outcomes of patients with AMM, and to devise a staging system predictive of survival outcome.

MATERIALS AND METHODS

This was a retrospective study of 28 patients diagnosed with, and treated for AMM. Patients classified by clinical staging of mucosal melanoma (MM) were reclassified via rectal and anal TNM staging. Survival outcomes were compared among patients grouped by the three different staging systems.

RESULTS

The three staging systems were equated with similar figures for 5-year overall survival (OS) and 5-year disease-free survival (DFS) of patients diagnosed with stage I disease. Patients (n=19) diagnosed with MM stage II disease were reclassified by rectal TNM staging into three subgroups: IIIA, IIIB, and IIIC. For these patients, both 5-year OS and 5-year DFS differed significantly between the subgroups IIIA and IIIC (OS: IIIA vs. IIIC, 66.7% vs. 0%, p=0.002; DFS: IIIA vs. IIIC, 51.4% vs. 0%, p < 0.001).

CONCLUSION

The accuracy of prognosis in patients diagnosed with AMM and lymph node metastasis has improved by using rectal TNM staging, which includes information regarding the number of lymph node metastases.

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.

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.

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

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: A case report with extended follow-up

Background:

Anorectal melanoma is a rare and aggressive disease. The mainstay of treatment is usually surgical with curative or palliative intent, since radio- and chemotherapy do not really improve the outcome. The poor prognosis is attributable to delay in diagnosis and its inherent biologic aggressiveness.

Case Report:

We present a case of anorectal melanoma in a 68-year-old man who underwent solely abdominoperineal amputation and was doing well 30 months after surgery, without any evidence of recurrent disease.

Conclusions:

Treatment of anorectal melanoma should be by the least morbid means possible. Surgical procedure that can achieve a complete local excision and respect the functional aspects and quality of life of the patient remains the best therapeutic approach. No systemic regimen for metastatic anorectal melanoma is considered standard of care.

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.

Treatment outcomes of anorectal melanoma

Purpose

An anorectal melanoma (AM) is a very rare tumor. However, sufficient data supporting effective surgical options for the disease do not exist. This retrospective review aimed to analyze treatment outcomes for an AM.

Methods

From June 1999 to December 2008, we retrospectively reviewed a prospectively collected consecutive series of 19 patients who had undergone a surgical resection for an AM at a single institute. Surgical method and clinicopathological factors were analyzed.

Results

The median age was 61.4 years (range, 46 to79 years). Main symptoms were an anal mass, hematochezia, perianal pain, tenesmus, fecal incontinence, and bowel habit change. The average duration of symptoms before diagnosis was 7.8 months (range, 1 to 36 months). S-100 and HMB-45 were positive in all patients, even in non-melanin pigmentation. There were 12 abdominoperineal resections (APRs) and 7 wide local excisions (WEs). The APR showed longer overall survival when compared with the WE (64.1 months vs. 10.9 months, P < 0.001). No patients who underwent a WE survived more than 13 months.

Conclusion

A high index of suspicion is necessary to establish the diagnosis for an AM in patients with anal symptoms, and S-100 and HMB-45 can be useful markers for an AM. Even with the small number of cases and the short follow-up, our data suggest that an APR for an AM may provide longer survival than a WE.