Year: 2025
Type: conference-abstract
Abstract: Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumour that derives from the Merkel cells within the epidermis. The pathogenesis principally involves cell DNA mutations from long-term ultraviolet (UV) radiation exposure or the presence of Merkel cell polyomavirus (MCPyV). The majority of MCCs satisfy at least three features of the widely accepted ‘AEIOU’ acronym: Asymptomatic, Expanding rapidly, Immunosuppression, Over 50 years old, UV-exposed site. There is limited literature describing the key clinical and morphological features of this tumour. The aim of this case series is to showcase the clinical variability of both early and advanced MCC and to identify and describe the common morphological features at presentation. A business intelligence platform (BOXI) search was performed using the term ‘Merkel cell tumour’ to identify pathologically confirmed cases of MCC over a 15-year period between July 2009 and July 2024, across two skin cancer centres. The authors searched Medical Image Manager (MIM) to identify whether clinical photographs of lesions were available. Two expert authors reviewed the images to achieve consensus on morphological descriptors. Demographic data were collected retrospectively. Over 15 years, 110 biopsy-proven cases of MCC were identified. Of these, 30 had clinical images available and were included (16 male, 14 female). The median age at diagnosis was 82 years (range 61–93). Eight (27%) individuals were immunosuppressed at the time of diagnosis. Twelve (40%) of the 30 people had documented lymphadenopathy. At presentation, 20 of 30 (67%) tumours were > 2 cm in diameter. In total, 29 of 30 (97%) were located in sun-exposed sites, 25 of 30 (83%) were erythematous, 27 of 30 (90%) were nodular, 18 of 30 (60%) were ulcerated and 14 of 30 (47%) were keratinized. There is a lack of familiarity regarding the morphological features of MCC, attributable to its low prevalence. In this retrospective case series, most MCC tumours presented as erythematous nodules > 2 cm in diameter, with ulceration. Many were also noted to have keratinization. MCC has a significantly lower survival rate than melanoma, and its incidence is increasing, likely due to the ageing population (Samiha T Mohsen, Emma L Price et al. Incidence, mortality and survival of Merkel cell carcinoma: a systematic review of population-based studies. Br J Dermatol 2024; 190: 811–24). Therefore, it is essential that dermatologists are aware of the common morphological features of MCC. This will result in a higher index of suspicion, reduce delay in diagnosis and potentially improve overall prognosis.
Source: British Journal of Dermatology
Authors: Katie Heinz, Jennifer McGuire, Asok Biswas, Megan Mowbray
Institutions: NHS Lothian, NHS Fife
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4411733166