Nodular hidradenoma of the breast mimicking breast cancer in a postmenopausal woman: a rare clinical entity

Abstract Background Nodular hidradenoma presents a diagnostic challenge due to its rare occurrence and varied clinical appearances. It usually occurs in the head and neck region, but when it occurs in the skin overlying the breast tissue, it may mimic breast cancer, leading to clinical and radiological confusion. This benign tumor originates from sweat gland cells and typically manifests as a slow-growing, painless nodule in the skin. Accurate diagnosis is essential to prevent undue concern and unwarranted treatment, particularly when it resembles more serious conditions such as breast cancer. Case presentation We present sonomammography and one of the few published magnetic resonance imaging (MRI) correlates of nodular hidradenoma of the breast. We report the case of a 49-year-old woman with a complex cystic and solid mass in the left breast on ultrasonography that was assessed as breast imaging reporting and data system (BI-RADS) category 4b. Conclusion Nodular hidradenoma is a very rare entity in the breast and lacks characteristic clinical and radiological features. Radiologists must remain vigilant regarding nodular hidradenoma and include it in the list of potential diagnoses for breast nodules, particularly in instances of atypical presentation or when typical features of breast cancer are absent. A biopsy and histopathological analysis are typically necessary for definitive diagnosis, aiding differentiation from malignant lesions.