Primary Cutaneous Umbilical Melanoma: The Michigan Experience.

BACKGROUND: Primary cutaneous umbilical melanoma is rare. Thorough information regarding its characteristics and treatment, including use of sentinel lymph node biopsy (SLNB) staging, is difficult to obtain. The unique anatomy of the umbilicus adds to the complexity of diagnosing and treating melanoma at this site. OBJECTIVE: To improve understanding of diagnosis and treatment of primary cutaneous umbilical melanoma through presenting 7 new cases and reviewing 39 cases in the literature. MATERIALS AND METHODS: The University of Michigan melanoma database query and review of the literature regarding reported cases of primary umbilical melanoma. RESULTS: In 7 new and 39 previously reported cases of primary cutaneous umbilical melanoma, we describe signs and symptoms, histopathologic features, differential diagnosis, relevant anatomical considerations, and definitive treatment including SLNB when applicable. CONCLUSION: Our series, combined with a thorough literature review and compilation of findings, provides a better understanding and appreciation of melanoma in the unique anatomical site of the umbilicus, with a reminder to carefully examine the umbilicus during a full skin examination in patients at risk of melanoma. Primary umbilical melanoma presents and can be appropriately treated similarly to cutaneous melanoma in other sites, with attention to relevant anatomy.

Gynecologic melanomas: A clinicopathologic and molecular analysis.

OBJECTIVE: Melanoma originating from gynecologic sites (MOGS), including the vulva, vagina, and cervix, is a rare and aggressive form of melanoma with poor long-term clinical outcome. The clinicopathologic features of vulvar and non-vulvar tumors remain relatively understudied, and in contrast to cutaneous melanomas at non-sun-exposed sites, MOGS typically do not harbor BRAF mutations. Thus, we sought to analyze the clinicopathologic and molecular features of MOGS. METHODS: A large retrospective cohort of patients with MOGS (n=59) at a single large academic institution over a 28-year period was identified. Associations among clinicopathologic characteristics were assessed via standard statistical approaches, and clinical outcome was examined using Cox regression analysis. Sanger sequencing was utilized to identify mutations in hotspot regions of BRAF, KIT, NRAS, and CTNNB1. RESULTS: Tumors involving the vagina and/or cervix (non-vulvar) are significantly associated with high-risk clinicopathologic features, including increased tumor thickness, ulceration, positive resection margins, lymph node metastasis, and poor long-term clinical outcome (with increased risk of death due to disease). The aggressive clinical behavior of non-vulvar tumors is independent of advanced clinical stage and lymph node metastasis in multivariate analysis. Targeted molecular analysis confirms an overall low rate of oncogenic mutations in our MOGS cohort, although KIT mutations (particularly in exon 11) are relatively enriched. CONCLUSIONS: Overall, our results show that non-vulvar MOGS are aggressive tumors with poor long-term clinical outcome and indicate that few targeted therapeutic options are currently available to patients with MOGS.

The natural history of thin melanoma and the utility of sentinel lymph node biopsy.

BACKGROUND AND OBJECTIVES: Current literature may overestimate the risk of nodal metastasis from thin melanoma due to reporting of data only from lesions treated with SLNB. Our objective was to define the natural history of thin melanoma, assessing the likelihood of nodal disease, in order to guide selection for SLNB. METHODS: Retrospective review. The primary outcome was the rate of nodal disease. Clinicopathologic factors were evaluated to find associations with nodal disease. RESULTS: Five hundred and twelve lesions, follow up available for 488 (median: 48 months). Lesions treated with WLE/SLNB compared to WLE alone were more likely to have high-risk features. The rate of nodal disease was higher in the WLE/SLNB group (24 positive SLNB, five false-negative SLNB with nodal recurrence: 10.2%) compared to WLE alone (four nodal recurrences: 2.0%). Univariate analysis showed age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm2 , and ulceration were associated with nodal disease. Multivariate analysis confirmed the association of age ≤45 and ulceration. CONCLUSIONS: SLNB for melanoma 0.75-0.99 mm should be considered in patients age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm2 , and/or with ulceration. Thin melanoma <0.85 mm without high-risk features may be treated with WLE alone.