Clear Cell Hidradenoma with Extensive Mucinous Change in the Axillary Tail of Breast as Mimicker: A Rare Case Report

Introduction: Clear cell hidradenoma (CCH) is a rare benign tumor of sweat gland. It can mimic other diseases clinically, radiologically and histologically when found in axilla. Methods: A 62-year-old female presented with a solitary lump in the axillary tail of her breast. Differentials in clinical examination and imaging were breast neoplasm and lymph nodal mass. Results: The patient underwent preoperative diagnostic workup, and the lesion was suspicious of hidradenoma. She underwent wide excision of the lesion. The final histopathological examination was suggestive of CCH with extensive mucinous change. Conclusion: Even though rare, hidradenoma should always be kept as a differential when presented as a solitary painless swelling. The present case represents diagnostic challenges involved during the course of her management and accurate use of preoperative tools, which helped in the diagnosis of the case before the definitive treatment.