We present the cytological findings of a rare case of crystallising galactocele. A 37-year-old woman presented with an approximately 2-month history of a non-tender breast lump detected during self-examination. She had been breastfeeding until approximately 8 months before the lump was detected. Ultrasound revealed a 10 mm solid lesion. She underwent ultrasound-guided fine-needle aspiration cytology. The preparations revealed isolated epithelial and apocrine cells in a background of macrophages, blood, and cellular debris. Clusters of amorphous material and abundant birefringent crystalline materials were also seen under polarised microscopy. No malignant cells were identified. Given the patient’s lactation history and cytological findings, a diagnosis of crystallising galactocele was made. On follow-up over the last 7 years, the lesion slowly reduced in size but did not fully resolve. Crystallising galactocele creates diagnostic challenges, both clinically and radiologically, owing to its reported solid morphology. Fewer than 15 cases of crystallising galactocele have been reported in the literature. In conclusion, the main aim of this case report is to increase awareness of this rare entity and present the cytological features of crystallising galactoceles.
Kawatu et al. (Sun,) studied this question.