Spuriously aggressive features of a lactating adenoma prompting repeated biopsies

Abstract

We present an atypical presentation of a common pregnancy-related breast mass, a lactating adenoma with imaging and pathologic correlation. The patient presented with a rapidly enlarging left breast mass associated with skin changes and severe pain in the perinatal period. Core biopsies were considered discordant, and the patient went on to surgical excision for the definitive diagnosis of an infarcted lactating adenoma. The symptoms of infarction may obscure the diagnosis of common entities and result in additional evaluation.

Keywords: Infarction; Lactating adenoma.

Fig. 1

Preoperative photograph shows large left breast mass with skin erythema and ulceration from prior biopsy site (arrow).

Fig. 2

Ultrasound images of mass. (A) Antiradial ultrasound image of left breast mass showing medial half of the left breast is virtually replaced by a large, solid mass with mixed echogenicity. (B) Antiradial Doppler ultrasound image demonstrating the mass is avascular. (C) Unsuccessful aspiration attempt, with needle (arrows) within the solid mass. No fluid or blood was aspirated.

Fig. 3

Gross photograph shows spongy, lobular, tan mass which is largely necrotic, measuring at least 16 cm in length.

Fig. 4

Histology of lactating adenoma. (A) Low power view demonstrates zonal pattern of infarction. Bottom half of image shows ghost outlines of glands (arrows). Top half shows viable tissue (H&E 40×). (B) Intermediate power view demonstrates lactational changes with cells that have basophilic cytoplasm, hyperchromatic nuclei, and prominent nucleoli. Secretions accumulate in the glands (arrows) (H&E, 200×). (C) Photomicrograph of left breast mass demonstrates closely packed glands with apical cytoplasmic blebs and fraying of the luminal border (arrows). There is an inconspicuous myoepithelial layer and no atypia to suggest malignancy (H&E, 200×).