Clinical presentation
A 53-year-old Asian female with no personal or family history of skin cancer presented to the clinic with a several year history of a tender pink lesion on the right foot. Clinical examination showed a 4 × 4 mm well-circumscribed, firm, pink-to-flesh colored papule on the right medial dorsal foot (Fig 1, A).
Fig 1.
A, Macroscopic physical examination: a 4 mm pink papule with focal areas of erythema located on the right medial dorsal foot. B, Dermoscopic features: a milky-white-to- pale pink papule with both hairpin (whitestar), and glomeruloid vessels (red arrow), white circles (yellow star), and multifocal areas of large orange clods (blue arrow). C, Histological examination showing atypical squamous proliferation with keratinocytes with clear cytoplasm, nuclear pleomorphism, and mitosis (40× magnification).
Dermatoscopic appearance
Dermoscopy revealed a pale pink background featuring both hairpin and glomeruloid vessels, along with white circles and multifocal areas of large orange clods (Fig 1, B).
Histologic diagnosis
A biopsy was obtained which revealed superficial well differentiated squamous cell carcinoma with clear cell features with p63 and p53 positivity and no signs of erosion noted on pathology (Fig 1, C).
Key message.
Squamous cell carcinoma (SCC) is the second most common type of nonmelanoma skin cancer; however, it is clear cell variant is rare, with only a few cases documented in the literature.1 While dermoscopic features of cutaneous SCC, such as white circles, blood spots, and keratin masses, are well-established diagnostic clues, detailed dermoscopic descriptions specific to clear cell SCC remain scarce due to its rarity.2 In this case, dermoscopic features typical of SCC were observed. However, the presence of large orange clods and an overall whitish-to-pale pink background may represent new characteristics associated with the clear cell variant. However, further case reports and detailed descriptions are needed to confirm these findings.
Conflicts of interest
None disclosed.
Footnotes
Funding sources: None.
Patient consent: The authors obtained written consent from patients for their photographs and medical information to be published in print and online and with the understanding that this information may be publicly available. Patient consent forms were not provided to the journal but are retained by the authors.
IRB approval status: Not applicable.
References
- 1.Souza E.N., Diniz L.M., de Moura L.A., Oliosi A.C., de Azevedo M.S.S., Souza M.N. Invasive clear-cell variant of squamous cell carcinoma mimicking sebaceous carcinoma. An Bras Dermatol. 2023;98(5):715. doi: 10.1016/j.abd.2022.05.007. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Rosendahl C., Cameron A., Argenziano G., Zalaudek I., Tschandl P., Kittler H. Dermoscopy of squamous cell carcinoma and keratoacanthoma. Arch Dermatol. 2012;148(12):1386–1392. doi: 10.1001/archdermatol.2012.2974. [DOI] [PubMed] [Google Scholar]