Challenging diagnosis of male intraductal papilloma masquerading as eccrine hidradenoma in the breast: Case report.

Rationale: This article presents a challenging case involving an elderly male patient with a misdiagnosed intraductal mammary papilloma initially identified as a sweat adenoma through ultrasound imaging. The study aims to explore the histopathology, clinical presentations, and sonographic features of both conditions, emphasizing the contributing factors to the diagnostic misstep.

Patient Concerns: A 61-year-old male reported a persistent left breast mass, along with pain and swelling, spanning a 6-month duration.

Diagnoses: Ultrasound examination indicated a deep, square, mixed-echo mass in the left nipple, initially suggestive of a sweat adenoma. However, subsequent pathological analysis following resection under general anesthesia confirmed an intraductal papilloma.

Intervention: The patient underwent surgical resection of the left breast mass under general anesthesia.

Outcome: Post-surgery, the patient exhibited satisfactory recovery; however, regrettably, he was lost to follow-up.

Lessons: This study underscores the challenge in differentiating between clear cell sweat adenoma and male intraductal mammary papilloma solely based on ultrasonic characteristics. It emphasizes the susceptibility of ultrasound-based diagnoses to misinterpretation, highlighting the critical need for a comprehensive pathological examination to establish a definitive diagnosis.