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.

Mohs Surgery versus Standard Local Excision for Basal Cell Carcinoma, Squamous Cell Carcinoma, and Melanoma Skin Cancer.

Basal cell carcinoma, squamous cell carcinoma, and melanoma represent the three most common skin cancers that occur on the face. The most common surgical treatments for facial skin cancers are Mohs' surgery and standard local excision. The effective utilization of either of these techniques is based on tumor and patient risk stratification incorporating known risk factors for occult invasion and local recurrence, combined with patient comorbidities, expectations, and desires. Best available evidence highlights multiple and consistent risk factors for each specific skin cancer type, and dictate local control rates reported in the literature. Recognizing gaps in the literature, we compare and review surgical treatment guidelines and data for standard local excision versus Mohs' surgery for cutaneous nonmelanoma and melanoma skin cancer. This article serves as a resource for optimal therapeutic decision making for surgical management of skin cancer on the face.

Dermal damage promoted by repeated low-level UV-A1 exposure despite tanning response in human skin.

IMPORTANCE: Solar UV irradiation causes photoaging, characterized by fragmentation and reduced production of type I collagen fibrils that provide strength to skin. Exposure to UV-B irradiation (280-320 nm) causes these changes by inducing matrix metalloproteinase 1 and suppressing type I collagen synthesis. The role of UV-A irradiation (320-400 nm) in promoting similar molecular alterations is less clear yet important to consider because it is 10 to 100 times more abundant in natural sunlight than UV-B irradiation and penetrates deeper into the dermis than UV-B irradiation. Most (approximately 75%) of solar UV-A irradiation is composed of UV-A1 irradiation (340-400 nm), which is also the primary component of tanning beds. OBJECTIVE: To evaluate the effects of low levels of UV-A1 irradiation, as might be encountered in daily life, on expression of matrix metalloproteinase 1 and type I procollagen (the precursor of type I collagen). DESIGN, SETTING, AND PARTICIPANTS: In vivo biochemical analyses were conducted after UV-A1 irradiation of normal human skin at an academic referral center. Participants included 22 healthy individuals without skin disease. MAIN OUTCOMES AND MEASURES: Skin pigmentation was measured by a color meter (chromometer) under the L* variable (luminescence), which ranges from 0 (black) to 100 (white). Gene expression in skin samples was assessed by real-time polymerase chain reaction. RESULTS: Lightly pigmented human skin (L* >65) was exposed up to 4 times (1 exposure/d) to UV-A1 irradiation at a low dose (20 J/cm2), mimicking UV-A levels from strong sun exposure lasting approximately 2 hours. A single exposure to low-dose UV-A1 irradiation darkened skin slightly and did not alter matrix metalloproteinase 1 or type I procollagen gene expression. With repeated low-dose UV-A1 irradiation, skin darkened incrementally with each exposure. Despite this darkening, 2 or more exposures to low-dose UV-A1 irradiation significantly induced matrix metalloproteinase 1 gene expression, which increased progressively with successive exposures. Repeated UV-A1 exposures did not suppress type I procollagen expression. CONCLUSIONS AND RELEVANCE: A limited number of low-dose UV-A1 exposures, as commonly experienced in daily life, potentially promotes photoaging by affecting breakdown, rather than synthesis, of collagen. Progressive skin darkening in response to repeated low-dose UV-A1 exposures in lightly pigmented individuals does not prevent UV-A1-induced collagenolytic changes. Therefore, for optimal protection against skin damage, sunscreen formulations should filter all UV wavelengths, including UV-A1 irradiation.