Rationale:
The ultrasound manifestations of granular cell tumor (GCT) is a consequence of the histopathological characteristic of the tumor and can be distinguished from breast cancer.
Patient concerns:
A GCT is a rare, benign, hyperplasia-based lesion. Approximately 1% to 2% of GCTs are malignant. About 5% to15% of the cases occur in the breast, and it is relatively rare in the axillary accessory breast. There are no effective preventive measures for GCTs, early detection combined with a thorough and wide complete resection of the tumor remains the best treatment for a favorable outcome.
Diagnoses:
A 45-year-old female patient with an axillary mass of more than 3 months duration was examined through physical examination, color Doppler ultrasound and postoperative pathology.
Interventions:
A provisional diagnosis of left axillary lymph node enlargement was made and necessary investigations were advised.
Outcomes:
A differential diagnosis of accessory breast in the left arm pit, possibly malignant, or a solid mass in the left arm pit secondary to chronic inflammation. Postoperative pathology: GCT of axillary accessory breast, with tumor-free margins. Immunohistochemical staining showed strong S-100 positivity, CD68 positivity, and negative periodic acid-Schiff staining.
Lessons:
The ultrasound examination can detect GCT mass in the breast/accessory breast and is not easy to misdiagnosis.