Anorectal Melanoma Research Articles

Single-cell transcriptomics reveals hypoxia-driven iCAF_PLAU is associated with stemness and immunosuppression in anorectal malignant melanoma.

Anorectal malignant melanoma (ARMM) is a refractory malignancy that not only responds poorly to radiotherapy but also to immunotherapy. Tumor microenvironment (TME) components play an essential role in tumor progression and therapeutic response. However, TME characteristics of ARMM are not well understood. We conducted a single-cell RNA sequencing on tumor and blood tissue from three ARMM patients, and combined with cutaneous melanoma datasets from the Gene Expression Omnibus database for a comprehensive joint analysis. Our findings revealed that cancer cells have four major patterns of chromosomal mutations. ARMM cancer cells exhibited marked intratumoral heterogeneity, and elevated angiogenesis, hypoxia, stemness, and epithelial-mesenchymal transition characteristics. We also identified the cancer stem cell subpopulation c5_Mel_CD55_VEPH1 in ARMM. Notably, we observed that CD8 + T cells in ARMM were poorly infiltrated and predominantly in a terminal exhausted state. Moreover, we identified a unique population of PLAU + fibroblast cells (iCAF_PLAU) in ARMM that likely have differentiated from myofibroblasts under hypoxic conditions. The iCAF_PLAU population enhances the stemness and aggressiveness of cancer cells through the ligand-receptor pairs WNT5A_FZD3_LRP6 and NRG1_ERBB3. In addition, iCAF_PLAU secretes CCL2, which binds to CCR1 on SPP1 + macrophages (TAM_SPP1) cells, leading to the activation of NFKBIA in TAM_SPP1 and subsequent upregulation of IL6, which may be linked to the exhaustion process of CD8 + T cells. Immunofluorescence staining confirmed the co-localization of iCAF_PLAU with TAM_SPP1 and TAM_SPP1 with CD8 + T cells. Our data suggest a potential role of iCAF_PLAU in mediating cell-cell interactions within the TME of ARMM, highlighting potential therapeutic targets for this aggressive malignancy.

Case Report: Surgical management and prognostic factors in primary anorectal melanoma: a retrospective analysis of nine cases

BackgroundPrimary Anorectal malignant melanoma (pARMM) is an exceedingly rare and aggressive malignancy, accounting for approximately 1% of anorectal cancers. It originates from melanocytes in the anorectal mucosa and lacks distinctive clinical features, leading to frequent misdiagnosis and advanced presentation.MethodsA retrospective analysis was conducted on 9 patients (1 male, 8 females; median age 59 years) with histopathologically and immunohistochemically confirmed ARMM who underwent surgical resection (Wide Local Excision, WLE = 4; Abdominoperineal Resection, APR = 5) and had complete follow-up data (median 19 months, up to May 2025). Diagnostic methods included clinical evaluation, digital rectal exam (DRE), colonoscopy, imaging (CT), histopathology, and immunohistochemistry (IHC). Treatment approaches and outcomes were analyzed.ResultsCommon presenting symptoms were hematochezia (44.4%), tenesmus (22.2%), altered bowel habits, anal mass protrusion, or were asymptomatic (11.1% each). DRE revealed exophytic (n = 6) or polypoid (n = 3) masses. Colonoscopy showed lesions near the dentate line; only 33.3% had obvious pigmentation. IHC positivity: HMB-45/Melan-A 66.7%, S-100 55.6%. Pathological R0 resection was achieved in all patients. During follow-up, 3 patients (33.3%) developed distant metastases (lung, liver), 2 of whom died. Six patients remained disease-free.ConclusionPrimary Anorectal malignant melanoma (pARMM) often presents with symptoms mimicking common benign anorectal conditions, leading to frequent diagnostic errors. Definitive diagnosis requires histopathological examination, with immunohistochemical markers (HMB-45 and Melan-A positivity) providing critical confirmation. While surgical resection remains the primary treatment, a growing expert consensus supports wide local excision with adequate margins (≥1 cm) as sufficient management. Emerging evidence indicates comparable survival outcomes to more radical procedures in appropriately selected patients.

Sex differences in survival of anal melanoma: An analysis of the United States National Cancer Database.

e21607 Background: Mucosal melanoma is a rare, more aggressive subtype of melanoma, accounting for < 2% of all melanomas and associated with a poorer prognosis than cutaneous malignant melanomas. It can occur in any part of the body that contains melanocytes, including anywhere along the gastrointestinal tract with the anorectal region being the most common location. Patients with anorectal melanoma typically present with late-stage disease and treatment options are not well established given the rarity of the disease. Although sex differences in survival have been observed for cutaneous melanomas, with females having a survival advantage over males, sex differences in survival have not been well established in anal melanoma. This study aimed to compare the survival outcomes of anal melanoma between male and female patients using a national registry from the United States. Methods: Adult patients who were diagnosed with anal melanoma were identified from the National Cancer Database (NCDB) of Anal Cancer from 2005 to 2022 based on ICDO-3 codes. Patients undergoing palliative care were excluded. Overall survival (OS) was analyzed using Kaplan-Meier (KM) plots, log-rank tests, and Cox proportional hazard models that controlled for age, race and ethnicity, primary payor, income, education, facility type/location, comorbidities, treatment, and TNM staging. Results: Among the patients with anal melanoma, 594 were males and 873 were females. Males had a shorter mean OS (p < 0.01; Table). KM curves of the two groups were created, and a log-rank test showed a statistically significant difference in survival rates (p = 0.04). After multivariable analysis, OS remained significantly lower in male patients (HR 1.240, 95 CI 1.087-1.416, p < 0.01). Landmark survival rates of males were lower than that of females at 3 years [0.338 (95 CI 0.299-0.380) vs 0.400 (95 CI 0.366-0.435), p = 0.02] and 5 years [0.230 (95 CI 0.194-0.269) vs 0.284 (95 CI 0.250-0.319), p = 0.02] (Table). Conclusions: Males with anal melanoma exhibit worse survival outcomes compared to females, which is consistent with the known survival differences in cutaneous melanoma. Further research is needed to investigate the underlying mechanisms behind these differences and to develop targeted treatment strategies. Overall mortality, mean survival time, and landmark survival rates between male and female patients with anal melanoma. Male(n = 594) Female(n = 873) p-value Overall mortality (n, %) 421 (70.88%) 581 (66.55%) 0.09 Survival month (mean ± SE) 48.35 ± 2.73 59.41 ± 2.71 <0.01 Landmark survival rates (%, 95 CI) 6-month 0.883 (0.853-0.907) 0.885 (0.861-0.905) 0.91 1-year 0.734 (0.695-0.769) 0.744 (0.711-0.771) 0.67 2-year 0.501 (0.458-0.543) 0.511 (0.475-0.545) 0.71 3-year 0.338 (0.299-0.38) 0.400 (0.366-0.435) 0.02 5-year 0.230 (0.194-0.269) 0.284 (0.366-0.435) 0.02 Abbreviations: CI, confidence interval; SE, standard error.

Anorectal Melanoma: Case Report and Literature Review

Anorectal mucosal melanoma is an uncommon and highly aggressive form of mucosal melanoma. Its rarity makes clinical diagnosis difficult, and its initial symptoms are generally non-specific, such as rectal bleeding (the most frequent symptom), anal pain or the presence of an anal mass. The prognosis for this disease is generally poor, and its incidence seems to be increasing every year. Anorectal mucosal melanoma often goes undetected and/or is already metastasized at the time of diagnosis. We present a case report of a patient who initially presented with nonspecific symptoms of anemia and rectorrhagia and was later found to have melanoma of the anorectal region. There is a notable paucity of literature on this disease, resulting in a lack of overall understanding of its nature. Most of the information available is in the form of isolated case reports rather than comprehensive studies. Although surgical resection remains the primary treatment approach, the majority of patients (over 80%) will die from distant metastases within five years of surgery. The five-year survival rate for anorectal melanoma is estimated at between 6% and 22%.

A case of anastomotic recurrence 12years after intersphincteric resection for anorectal malignant melanoma.

Anorectal malignant melanoma (AMM) is a rare disease with a poor prognosis, accounting for < 1.0% of all malignant melanomas and a 5-year survival rate of 19.2%. The treatment is mainly surgical, and lymph-node dissection is often performed. Cases of recurrence after a prolonged period (> 10years), as in the present case, are rare. The patient was an 80-year-old woman who underwent laparoscopic intersphincteric resection with bilateral lateral lymph-node dissection for the diagnosis of primary AMM of the lower rectum at X -12years. The pathology was pStage III and the resection margins were negative. Twelve years after the initial surgery, in year X, the patient visited our hospital with the chief complaint of discomfort due to a tumor in the anorectal region. Biopsy revealed a recurrence, and laparoscopic abdominoperineal resection was performed. Based on the pathological findings, the patient was diagnosed with local recurrence of the anastomotic anal canal. Both the first and second specimens were negative for BRAF V600E/K mutation. Four months have passed since the surgery, and the patient continued to receive nivolumab without recurrence. Long-term local follow-up is necessary when the anal canal is preserved during AMM surgery.

Association of Log Odds of Positive Lymph Nodes with Overall Survival in Patients with Primary Malignant Anorectal Melanoma: A Population-Based Study

Background Malignant anorectal melanoma (AM) is a rare tumor characterized by its aggressive behavior. To date, there has been no comprehensive investigation into the association between the log odds of positive lymph nodes (LODDS) and the prognosis of patients with malignant AM who have undergone surgical intervention. Methods Data were extracted from the Surveillance, Epidemiology and End Results (SEER) database for patients diagnosed with primary malignant AM who have undergone surgical intervention between 2000 and 2021. The Kaplan–Meier (KM) method with the log-rank test was used to compare survival curves between different LODDS groups. Multivariate Cox models were employed to evaluate the independent association between LODDS and overall survival (OS). An analysis to explore the potential influence of unmeasured confounders on the relationship between LODDS and OS was conducted using the E value. Results The study included a total of 126 eligible patients. KM analysis revealed that patients with low LODDS exhibited significantly improved OS compared to those with high LODDS (p < 0.001). The multivariate Cox analysis demonstrated that LODDS was independently associated with OS. The calculated E value suggested that the potential impact of unmeasured confounders on the association between LODDS and OS was likely minimal. Conclusion The findings indicate that LODDS is independently associated with the prognosis of patients with AM undergoing surgical intervention. These results may enhance clinicians’ understanding of the prognosis of this rare malignancy and provide a basis for guiding therapeutic decisions.

Unmasking the Hidden Threat: Anorectal Lesion Revealed as Malignant Melanoma in a Resected Rectal Polyp

ABSTRACT Melanoma is a malignant neoplasm arising from melanocytes, primarily affecting the skin. Anorectal mucosal melanoma (ARMM) is an exceedingly rare and aggressive cancer with a poor prognosis. We present a case of a middle aged caucasian male patient with a rectal polyp, bleeding, and discomfort during defecation. A per rectal examination revealed a protruding mass, leading to a diagnosis of a pedunculated rectal mass. Imaging studies confirmed a large mass along the anal canal. The mass was surgically resected, and histopathological examination revealed neoplastic cells consistent with malignant melanoma. Immunohistochemical marker studies confirmed the diagnosis. ARMM is often misdiagnosed due to its rarity and nonspecific symptoms, leading to delayed diagnosis and poor outcomes. Computed tomography (CT) scans aid in assessing disease extent, while immunohistochemical markers assist in confirming the diagnosis. Wide local excision is the mainstay of treatment, although its impact on prognosis is limited due to the systemic nature of the disease. Lymph node dissection may be necessary in specific cases. Further research is required to enhance understanding and establish standardized management approaches for ARMM.

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

Anorectal melanoma (ARM) represents a problematic scenario due to a 5-year overall survival (OS) rate below 20% and its increasing incidence. Due to its comparable OS, local surgery (LS) has replaced radical surgery (RS). Adjuvant chemotherapy (Adj-CHT) and adjuvant immunotherapy (Adj-IT) are common treatments for ARM, while neoadjuvant immunotherapy (Neo-IT) has not been investigated yet. This study aimed to determine the best treatment to improve the OS. Patients with non-metastatic ARM in the National Cancer 1Database (2011-2021) who underwent surgery and received Neo-IT, Adj-IT, or Adj-CHT were included. Two cohorts were created based on the surgical approach (LS or RS). In their respective cohorts, patients receiving Neo-IT, Adj-IT, or Adj-CHT were matched 1:1:1 based on age, tumor size and location, lymphovascular invasion, and nodal disease. Kaplan-Meier analyses compared the different groups' influence on the 3-year OS. Sixty patients were included in the LS cohort. Among them, there was no difference in the 3-year OS at the Kaplan-Meier analysis (Neo-IT 61%, Adj-IT 47.1%, and Adj-CHT 44%). Thirty-six patients were included in the RS cohort. Kaplan-Meier analysis for this group revealed that Neo-IT was a protective factor for 3-year OS (Neo-IT 71%, Adj-IT 11%, Adj-CHT 8%; p-value = 0.002). Neo-IT + RS seems to improve the 3-year OS compared to the other common treatments for ARM. Neo-IT + RS can be considered a valuable treatment since prospective trials are challenging for rare diseases. When RS is not feasible, Neo-IT + LS may be beneficial as the 3-year OS reaches 61%.

Primary Anorectal Melanoma: Report of Two Cases of a Very Rare Disease

Primary anorectal melanoma (PAM) is a rare and aggressive malignancy accounting for less than 1% of anorectal cancers and 1–3% of all melanomas. It typically presents with non-specific symptoms such as rectal bleeding, anal pain, and weight loss, often leading to delayed diagnosis. We report two clinical cases of PAM: the first in a 52-year-old man with advanced disease and poor response to immunotherapy, and the second in a 73-year-old woman treated with chemoradiotherapy due to surgical ineligibility. Diagnosis in both cases was confirmed by histopathological and immunohistochemical analyses (S100 and HMB45 positivity). Imaging revealed locally advanced tumors without initial distant metastases. These cases highlight the diagnostic challenges and lack of standardized therapeutic protocols in PAM. While surgical excision remains the mainstay of treatment, the roles of chemotherapy, radiotherapy, and immunotherapy are evolving and not yet fully established. Prognosis remains poor, with high metastatic potential and low survival rates. This report underscores the need for heightened clinical awareness and further research to optimize the management of this rare malignancy.

Comparative analysis of histological predictors of adverse course of anorectal melanoma and skin melanoma

Aim. Analysis of the effect of histological characteristics on the prognosis of anorectal melanoma (ARM) and melanoma of the skin.Materials and methods. The study is based on a retrospective single-center analysis of the results of treatment of two groups of patients: with ARM and cutaneous melanoma. N.N. Blokhin National Medical Research Center of Oncology in the period from 2005 to 2023 regarding ARM, were taken from the archives of the pathology department. In turn, a group of patients with cutaneous melanoma was recruited from the «Melanoma Pro» registry. Patients were matched by age, gender and stage of the disease. Disseminated patients were excluded from both groups. A univariate and multivariate analysis of the influence on relapse-free survival and overall survival (OS) of the main clinical characteristics, as well as selected histological prognostic markers of skin melanoma was carried out: multifocal growth, maximum tumor size, maximum Breslow thickness, presence or absence of ulceration, neurotropism and lymphovascular invasion, and depth of invasion (layer).Results. The study included 21 patients in each group with ARM and skin melanoma. The skin melanoma group included: stage I–II – 9 (42.9 %); stage III – 12 (57.1 %). Data on lymphovascular invasion were available in 68 patients (of which 15 (22.1 %) showed it, p = 0.03), on ulceration – in 428 patients (of which 207 (48.4 %) had it, p = 0.00001), on neurotropism – in 57 patients (of which 3 (5.3 %) showed it, p = 0.35). In the ARM group, there was a tendency for the influence of Breslow invasion of more than 20 mm (hazard ratio 1.028, 95 % confidence interval 0.998–1.060, p = 0.070) and the level of tumor invasion (layer) (hazard ratio 2.117, 95 % confidence interval 0.990–4.525, p = 0.053) on OS in the univariate analysis; in the multivariate analysis, none of the results showed a significant result for OS. In the melanoma group, the prevalence of OS and relapse-free survival among women did not influence our choice. In the skin melanoma group, none of the factors had a significant effect on OS and relapse-free survival in our sample.Conclusion. Despite the fact that the analysis of the effectiveness of using histological characteristics of skin melanoma showed their potential use as factors of adverse effect on relapse-free survival and OS in ARM, no reliable effect on prognosis was found in the skin melanoma group. Additional studies are needed.

Shedding Light on a Rare Condition a Case Report and Literature Review on Primary Anorectal Melanoma

Anorectal melanoma is a rare and highly aggressive cancer, representing 0.5-1% of anorectal tumors and 1-2% of all melanomas. It predominantly affects older adults, with nonspecific symptoms like rectal discharge and pain, often leading to misdiagnosis. We present the case of a 50-year-old diabetic female diagnosed with locally advanced anorectal melanoma, who underwent abdominal-perineal amputation but succumbed to an ischemic stroke four months post-surgery. Treatment options are debated, with surgery being the primary method, though the prognosis remains poor due to early metastasis. While newer therapies, including tyrosine kinase inhibitors and immunotherapy, offer potential, their effect on survival is unclear. This case underscores the importance of considering anorectal melanoma in patients with unexplained anorectal lesions.

Approaches to Surgical Management of Anorectal Melanoma in the Pre- and Post-Immunotherapy Eras.

Although revolutionary in cutaneous melanoma, immune checkpoint inhibitors have shown reduced efficacy in anorectal melanoma. Nevertheless, their emergence and the possibility of improved outcomes may have changed the surgical management paradigm. To review the surgical management of anorectal melanoma in pre- and postimmunotherapy eras. A retrospective cohort study from the Melanoma Institute Australia Research Database. A quaternary melanoma referral center. Patients with anorectal melanoma from 1958 to 2021 were included. The use of abdominoperineal resection and wide local excision were compared in pre- and postimmunotherapy eras from the first use in 2014. Type of surgery performed over time and overall survival. A total of 56 patients were identified with anal (57.1%), anorectal (16.1%), and rectal melanoma (26.8%). Initial management was abdominoperineal resection (37.5%), low anterior resection (3.6%), wide local excision (46.4%), and nonsurgical (12.5%) in metastatic or unresectable disease. Immunotherapy and targeted therapies were used in 21 patients (37.5%) from 2014, with no difference in mode of surgical management in pre- and postimmunotherapy eras ( p = 0.134). Five-year survival was 12.5% for the entire cohort, with no significant difference comparing patients receiving wide local excision or abdominoperineal resection (15.4% vs 14.3%, log rank p = 0.77). Involved margins were significantly associated with wide local excision (15.4% vs 4.8%, p = 0.016) with similar rates of local recurrence (15.4% vs 14.3%, p = 0.58). The rarity of anorectal melanoma resulted in a small cohort managed over 63 years. Early checkpoint inhibitor trials excluded patients with mucosal melanoma, limiting access in this cohort. Despite the introduction of immunotherapy, surgery remains pivotal in the management of anorectal melanoma. Surgical resection may be curative and prevent morbidity due to locoregional progression, but it can come at the cost of reduced quality of life. Centralized management in experienced centers should be encouraged for optimal multidisciplinary management. See Video Abstract . ANTECEDENTES:Si bien han sido revolucionarios en el tratamiento del melanoma cutáneo, los inhibidores de los puntos de control inmunitario han demostrado reducida eficacia en el tratamiento del melanoma ano-rectal. Sin embargo, su advenimiento y la posibilidad de obtener mejores resultados podrían haber cambiado el paradigma del tratamiento quirúrgico.OBJETIVO:Revisar el tratamiento quirúrgico del melanoma ano-rectal en las épocas previa y posterior a la inmunoterapia.DISEÑO:Estudio retrospectivo de cohortes de la base de datos de investigación del Instituto del Melanoma de Australia (MRD2).ESCENARIO:Centro de referencia cuaternaria para melanomas.PACIENTES:Pacientes con melanoma ano-rectal desde 1958 hasta 2021.INTERVENCIONES:Se comparó la resección abdominoperineal y la excisión local ampliada en las épocas previa y posterior a la inmunoterapia desde su primer uso en 2014.PRINCIPALES MEDIDAS DE RESULTADOS:Tipo de cirugía realizada a lo largo del tiempo y sobrevida general.RESULTADOS:Se identificaron 56 pacientes con melanoma anal (57,1%), ano-rectal (16,1%) y rectal (26,8%). El tratamiento inicial fue la resección abdominoperineal (37,5%), la resección anterior baja (3,6%), la excisión local amplia (46,4%) y el tratamento no quirúrgico (12,5%) en enfermedad metastásica o irresecable. Se utilizaron inmunoterapia y terapias dirigidas en 21 pacientes (37,5%) a partir de 2014 sin diferencias en el modo de tratamiento quirúrgico en las épocas previas y posteriores a la inmunoterapia ( p = 0,134). La supervivencia a 5 años fue del 12,5% para toda la cohorte sin diferencias significativas al comparar a los pacientes que recibieron escisión local amplia o resección abdominoperineal (15,4% frente a 14,3%, log rank p = 0,77). Los márgenes afectados se asociaron significativamente con una escisión local amplia (15,4% frente a 4,8% p = 0,016) con tasas similares de recurrencia local (15,4% frente a 14,3% p = 0,58).LIMITACIONES:El melanoma ano-rectal es poco frecuente, por lo que presentamos una pequeña cohorte tratada a lo largo de ocho décadas. Los primeros ensayos con inhibidores de puntos de control excluyeron a los pacientes con melanoma mucoso, lo que limitó el acceso en esta cohorte.CONCLUSIONES:A pesar del advenimiento de la inmunoterapia, la cirugía sigue siendo fundamental en el tratamiento del melanoma ano-rectal. La resección quirúrgica puede ser curativa y prevenir la morbilidad debido a la progresión locorregional, pero puede tener el costo de una calidad de vida reducida. Finalmente, debe promoverse el tratamiento centralizado en centros experimentados para un tratamiento multidisciplinario óptimo. (Traducción-Dr. Xavier Delgadillo ).

590 Clinicopathologic and Molecular Characterization of Primary Anorectal Mucosal Melanomas

590 Clinicopathologic and Molecular Characterization of Primary Anorectal Mucosal Melanomas

Feasibility and impact of sentinel lymph node biopsy in patients affected by ano-rectal melanoma

Feasibility and impact of sentinel lymph node biopsy in patients affected by ano-rectal melanoma

Anorectal melanoma: Report of two cases

Anorectal melanoma: Report of two cases

Rare Differential Diagnosis of Hemorrhoidal Disease: Primary Anorectal Melanoma; a Case Report and Review of the Literature

Rare Differential Diagnosis of Hemorrhoidal Disease: Primary Anorectal Melanoma; a Case Report and Review of the Literature

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

PurposeAnorectal melanoma (ARM) poses a significant challenge due to the lack of established guidelines and a 5-year overall survival rate of less than 20%. The only recognized death risk factors are positive lymph nodes and positive surgical margins. This study aimed to identify the risk factors for local/distant recurrences and death in a 22-year multi-institutional experience.MethodsAll patients who underwent curative surgical resection or were referred to after resection at the Mayo Clinic for non-metastatic ARM (2002–2024) were included. Risk factors for local/distant recurrences, and deaths were assessed through multivariable Cox regression.ResultsEighty-eight patients were included in the study. Seventy-eight percent of patients had anal melanoma and 22% rectal melanoma. Nineteen percent had clinically positive lymph nodes. The surgical margins were positive in 62% of local surgeries, while they were positive in 13% of radical surgery cases. The first recurrence was often a local recurrence (67%), followed by distant metastasis (21%), with an overall comparable overall survival between the two. Radiotherapy administration, radical surgery, and negative margins were associated with less local recurrence. Clinically positive lymph nodes and local recurrences increased the risk of developing distant metastasis over time. Clinically negative lymph nodes, radiotherapy administration, radical surgery, and negative margins all contributed to a reduced death risk.ConclusionLocal recurrences in ARM may influence distant metastasis and death more than what was previously believed. Positive surgical margins in local surgery were remarkably high, reaching 62%. Protective factors for local recurrence and death included radical surgery, negative surgical margins, and radiotherapy.

Real-World Evidence of the Prevalence of Driver Mutations in Anorectal Melanoma.

Anorectal melanoma is a rare neoplasm with an aggressive behavior and poor prognosis. Recently, recurrent gene mutations related to anorectal melanoma have been identified in a small series of cases, and this holds promise for targeted therapies, analogous to cutaneous melanoma. The purpose of this study was to analyze testing rates and prevalence of mutations in anorectal melanoma in the Dutch population. The Netherlands Cancer Registry and the Dutch Nationwide Pathology Databank were queried for all patients with a diagnosis of anorectal melanoma (2009-2019) and for whom a molecular analysis was performed. The genes that were tested and mutations that were reported were recorded. Mutation status was correlated with clinical characteristics. In the period 2009-2019, 121 patients were diagnosed with anorectal melanoma. A molecular analysis was performed for 81 (67%) using single gene testing and various next-generation sequencing panels. Testing rates increased from 53% in 2009-2012 to 73% in 2016-2019. In 29/81 (36%) analyzed tumors, one or more mutations were reported: mutations in KIT (16/70, 23%), CTNNB1 (3/20, 15%), NRAS (6/60, 10%), BRAF non-V600E (4/74, 5%), GNAS (1/19, 5%), KRAS (1/28, 4%), BRAF V600E (1/74, 1%), and SF3B1 (1/1). In this cohort, a positive correlation was found between BRAF mutation status and age. Mutation status did not correlate with sex, date of diagnosis, tumor stage or surgical treatment. Survival was not influenced by any mutation status. KIT was the most frequently mutated gene in the 81 analyzed anorectal melanomas in the period 2009-2019. With the increasing testing rates and use of next generation sequencing, the molecular landscape of anorectal melanomas is gradually being revealed. Adoption of broad mutation analysis will reveal potentially actionable targets for treatment of patients with anorectal melanoma.

Evidence of 18 F-FDG Utility in Rare Case of Metastatic Anal Melanoma With Prolonged Survival.

A 43-year-old woman presented with an anorectal mass at which time excision was performed, and biopsy revealed anorectal mucosal melanoma (AM), anal subtype. Postexcision, 18 F-FDG PET/CT identified residual melanoma, confirmed on biopsy. Recurrence was monitored every 3 months using 18 F-FDG, which identified a perirectal lymph node 2.5 years later positive for metastatic melanoma. Given the rarity of AM and often delayed diagnosis, patients often present with metastases, resulting in poor prognosis. This unique case of metastatic AM with prolonged survival of 7 years to date supports the implementation of 18 F-FDG in the diagnostics and monitoring of AM.

Survival Outcomes in Patients Undergoing Pelvic Exenteration for Pelvic Mucosal Melanomas: Retrospective Single Institution Australian Study.

Pelvic mucosal melanomas, including anorectal and urogenital melanomas, are rare and aggressive, with a median overall survival of up to 20 months. Pelvic mucosal melanomas behave differently from their cutaneous counterparts and present late with locoregional disease, making pelvic exenteration its only curative surgical option. This study aimed to evaluate the survival outcomes after pelvic exenteration in pelvic mucosal melanomas at Royal Prince Alfred Hospital. Retrospective case series from a prospectively collected pelvic exenteration database from October 1994 to November 2023. Royal Prince Alfred Hospital (quaternary institution), Camperdown, New South Wales, Australia. Seven patients undergoing pelvic exenteration for pelvic mucosal melanoma. Overall survival, disease-free survival, and complication rates. Of the 7 patients, most were women (n = 5; 71.4%) and had a median age of 65 years (range, 36-79). Five patients (71.4%) underwent pelvic exenteration for primary pelvic mucosal melanoma, 3 of which were anorectal and 2 vaginal melanomas. Two patients (28.6%) had recurrent anorectal melanoma and received neoadjuvant radiotherapy after an initial wide local excision. Three patients (42.9%) required total pelvic exenteration, whereas 2 required a central pelvic exenteration (28.6%). The remaining procedures included central and lateral pelvic exenteration and anterior, central, and lateral pelvic exenteration. The median length of hospital stay was 19.7 days. Five patients had postoperative complications with 1 major complication (Clavien-Dindo grade IIIa). At the completion of the study, there were 4 mortalities. Mean survival was 23.6 months (range, 2-100) with a recurrence rate of 83%. The median time to recurrence was 3 months, despite 6 patients (85.7%) having R0 resections. Distant recurrence, specifically to bone, the lungs, and the liver, was most common. Small study cohort due to rarity of disease, limiting generalizability. Pelvic exenteration for pelvic mucosal melanoma appears to help control local disease as recurrence is most commonly distant or regional. See Video Abstract . ANTECEDENTES:Los melanomas de la mucosa pélvica (MM), incluidos los melanomas anorrectales y urogenitales, son raros y agresivos, con una supervivencia global media de hasta 20 meses. Los melanomas de la mucosa pélvica se comportan de manera diferente a sus contrapartes cutáneas y se presentan tardíamente con enfermedad locoregional, lo que hace que la exenteración pélvica (EP) sea su única opción quirúrgica curativa.OBJETIVO:Este estudio tuvo como objetivo evaluar los resultados de supervivencia tras la exenteración pélvica en melanomas de la mucosa pélvica en el Royal Prince Alfred Hospital.DISEÑO:Serie de casos retrospectivos de una base de datos de exenteración pélvica recopilada prospectivamente desde octubre de 1994 hasta noviembre de 2023.ESCENARIO:Royal Prince Alfred Hospital (institución cuaternaria), Camperdown, Nueva Gales del Sur, Australia.PACIENTES:Siete pacientes sometidos a exenteración pélvica por melanoma de la mucosa pélvica.PRINCIPALES MEDIDAS DE RESULTADOS:Supervivencia general, supervivencia libre de enfermedad y tasas de complicaciones.RESULTADOS:De los siete pacientes, la mayoría fueron mujeres (n = 5, 71,4%) y tenían una edad media de 65 años (rango 36-79). Cinco pacientes (71,4%) fueron sometidos a una exenteración pélvica por melanoma primario de la mucosa pélvica; tres de los cuales eran melanomas anorrectales y dos vaginales. Dos pacientes (28,6%) tuvieron melanoma anorrectal recurrente y recibieron radioterapia neoadyuvante después de una escisión local amplia inicial.Tres pacientes (42,9%) requirieron una exenteración pélvica total, mientras que dos requirieron una exenteración pélvica central (28,6%). Los procedimientos restantes fueron una exenteración pélvica central y lateral; junto con una exenteración pélvica anterior, central y lateral. La duración media de la estancia hospitalaria fue de 19,7 días. Cinco pacientes tuvieron complicaciones postoperatorias con una complicación mayor (Clavien-Dindo IIIa). Al finalizar el estudio, hubo cuatro muertes. La supervivencia media fue de 23,6 meses (rango 2-100) con una tasa de recurrencia del 83%. El tiempo medio hasta la recurrencia fue de tres meses, a pesar de que seis pacientes (85,7%) tuvieron resecciones R0. La recurrencia distante, es decir, en hueso, pulmón e hígado fueron la más comúnes.LIMITACIONES:Cohorte de estudio pequeña debido a la rareza de la enfermedad, lo que limita la generalización.CONCLUSIÓN:La exenteración pélvica para el melanoma de la mucosa pélvica parece ayudar a controlar la enfermedad local, ya que la recurrencia es más comúnmente distante o regional. (Traducción-Dr Osvaldo Gauto ).