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Case Reports
. 2024 Dec 13;16(1):137-140.
doi: 10.4103/idoj.idoj_478_24. eCollection 2025 Jan-Feb.

Unsuspecting Plaque on the Forearm: A Diagnostic Challenge

Ramith P Shetty  1 , M Ramesh Bhat  1 , Myfanwy Joanne Dsouza  1 , Michelle S Fernandes  1
Affiliations
Case Reports

Unsuspecting Plaque on the Forearm: A Diagnostic Challenge

Ramith P Shetty et al. Indian Dermatol Online J. .

Abstract

Microcystic adnexal carcinoma (MAC) is a rare, slow-growing, locally aggressive malignant, and recurring appendageal tumor. Prolonged UV exposure, immunosuppression, and radiotherapy are a few frequently associated risk factors. MAC classically presents as an asymptomatic skin coloured plaque on the face. The key to diagnosis is a deep-sectioned biopsy. Surgical modalities are the first line of treatment.

Keywords: Appendageal tumor; microcystic adnexal carcinoma; skin cancer.

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Conflict of interest statement

There are no conflicts of interest.

Figures

Figure 1
Figure 1
A solitary, well-defined, firm to hard plaque of 5cm diameter over right forearm with a positive finger insinuation sign
Figure 2
Figure 2
Dermal tumor with neoplastic epithelial tadpole-shaped ducts with eosinophilic secretions giving a ‘paisley tie appearance’ (H and E Scanner view)
Figure 3
Figure 3
Keratin cyst in upper dermis (H&E, 400x)
Figure 4
Figure 4
Neoplastic epithelial tadpole-shaped ducts (H&E, 400x)
Figure 5
Figure 5
Immunohistochemistry showing S100 positivity
See this image and copyright information in PMC

References

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