Treatment of Microcystic Adnexal Carcinoma in a 52-year-old female patient during the COVID-19 Pandemic

Abstract

Introduction: Microcystic Adnexal Carcinoma (MAC) is a rare malignant sweat gland neoplasm. It is slow growing and locally aggressive but rarely metastasises. There have only been a few hundred cases described worldwide (1). During the COVID-19 pandemic, much elective surgery has been postponed, but due to the malignant nature of the lesion, this day case surgery is able to go ahead.

Methods: A 52-year-old female patient presented with a nodular lesion of the right medial eyebrow. Punch biopsy histology described a moderately differentiated squamous cell carcinoma. The lesion was excised and repaired with a local skin flap, and definitive histology reported MAC excised with 3mm margins. The case was discussed at a virtual multi-disciplinary team meeting which advised wider excision. This was undertaken with a supraclavicular full thickness skin graft to cover the defect. Both procedures were carried out as day cases; the patient was tested for COVID-19 and isolated beforehand.

Results: Histology described a highly infiltrative tumour not connecting with the overlying epidermis. It was composed of cords and nests of cells, manifesting ductular and follicular differentiation. The carcinoma invaded subcutaneous fat and perineural tissues. The cells were positive for cytokeratin AE1/AE3 and negative for BerEP4, overall favouring the diagnosis of MAC. Owing to the aggressive potential of this tumour, a wider margin was advised, the result of which was negative for malignancy.

Conclusion: MAC is a malignant tumour which often microscopically exceeds macroscopic margins, and presents clinically as a benign slow-growing lesion. This case follows the treatment of MAC during the COVID-19 pandemic.