Fig. 36.1 Sonography of the right breast. Panoramic view.

Clinical Findings

Segmental resistance in the lower outer quadrant of the right breast.

Fig. 36.2a,b Sonography.

Fig. 36.3a,b Conventional mammography, CC view [imaging not performed by authors].

Fig. 36.4a,b Conventional mammography, MLO view [imaging not performed by authors].

Fig. 36.5a–c Contrast-enhanced MRI of the breasts.

Fig. 36.6a–c Contrast-enhanced MRI of the breasts.

Fig. 36.7 Contrast-enhanced MR mammography. Maximum intensity projection.

Ultrasound

In the same area as the palpable segmental mass, US demonstrated multiple round lesions of varying sizes, all with homogeneous internal echo pattern and well-defined margins. There were linear hypoechoic structures surrounding each lesion, denoting their intraductal position. US BI-RADS right 3.

Mammography

Mammograms demonstrated bilaterally, mainly symmetric, inhomogeneous dense tissue, ACR type 3. Positioning of the right breast was inadequate, but round lesions were visible in the lower outer quadrant. There were no densities or architectural distortions. There were no calcifications. BI-RADS right 3/left 1. PGMI:CC view G (nipple not in profile); MLO view I (inadequate positioning of the entire right breast; parenchyma superimposed over the nipple).

MR Mammography

MRI showed multiple hyperintense round lesions in a segmental orientation in the right breast, consistent with ultrasound and clinical findings. Postcontrast images verified a marked enhancement of the milk duct walls in this area, while the intraductal lesions showed no contrast uptake. These lesions were hypointense in T2-weighted images.

In this case a signal-time curve analysis was not performed, because the intraductal lesions showed no enhancement. It seemed more relevant to perform an accurate analysis of the structures’ signal across the different sequences.

Differential Diagnostic Considerations

Intraductal blood pooling (Tl signal↑, T2 signal ↓)? Intraductal milk retention?

Stenosing milk duct near the nipple? Focal inflammation?

A malignant tumor can be excluded (no enhancement of the intraductal structures, T2 signal ↓).

Procedure

US-guided fine-needle aspiration cytology to identify the intraductal process in the lower outer quadrant of the right breast.

Cytology of the right breast

Eosinophilic protein-rich precipitate incorporating copious fat. Also, signs of a focal granulomatous inflammation.

Further procedure

At the express wish of the young patient, a wait-and-see approach was followed and follow-up sonography was performed at intervals of 2, 6, and 12 weeks. The patient declined repeat mammography to obtain better-quality images of the right breast. Finding after 20 weeks: Complete resorption of the intraductal fluid.

Fig. 36.8 Segmental distribution of the changes in panoramic view.

Fig. 36.9 Viscous fluid in aspirated specimen from the right breast.