Cysts: are they always benign?

Introduction

We present here four cases of atypical cysts. Cysts are one of the commonest benign lumps seen in a breast clinic. Rarely cysts can show some atypical features, on clinical assessment or on ultrasound.

Triple assessment

The patients were seen in the symptomatic clinic and had a triple assessment according to local protocol. Clinically all had a well-defined smooth lump suggestive of a benign lump, probably a cyst, but the ultrasound in these four patients showed atypical features and was graded as U3 (mammogram was R2). The 27 year old had internal echoes on ultrasound and aspiration was slightly blood stained. Cytology was reported as c3. The cyst rapidly re-accumulated in 3–4 weeks and was re-aspirated and was again blood stained. The other three patients had an ultrasound picture suggestive of a small pappilomatous lesion within the cyst, and guided aspiration revealed suspicious cells. All patients underwent excision of the lump, and the 27 year old had invasive carcinoma and the other three patients had intracystic carcinoma.

Discussion and conclusion

Atypical features on ultrasound in cysts need further investigation. Although cysts are very common benign problems they would need investigation if there were atypical features clinically or on ultrasound.