Cytological diagnosis of crystallizing galactocele – report of an unusual case

Introduction

Galactocele are the most common benign cystic lesion of breast occurring more commonly in pregnant and lactating females. A galactocele is a retention cystic tumor located in mammary gland, caused due to protein plugging of the outlet [1]. Crystallizing galactocele is a very rare entity which on Fine Needle Aspiration Cytology (FNAC) yield a viscous, chalky material which will be diagnostic for this rare condition. FNAC plays an important role in making the diagnosis of this entity [2]. Aspiration of the cystic content is also used as a treatment for this condition [2]. We report here this case because of rarity of this condition. To the best of our knowledge till date only five cases of Crystallizing galactocele has been reported in English medical literature [3].

Case Report

A 26 year old female was presented with a lump in her right breast with mild discomfort during breast feeding for last 8 months. The swelling measures 2 × 2 cm in size. The swelling was firm, discrete, non-tender and mobile involving the upper inner quadrant of right breast. One year back, she had delivered a baby by a spontaneous, full term, vaginal delivery. She had breast fed her child for six months and thereafter, intermittently to the day of presentation. The clinician advised an FNAC of the lesion that yielded thick, milky, chalky material. The swelling was reduced after the aspiration. Cytological smears showed numerous semitransparent positive birefringent crystals of varying size and shape with angulated borders (Fig. 1A). Background was of acellular, granular amorphous proteinaceous material along with frothy appearing micelles (Fig. 1B). No ductal elements or bipolar nuclei or fibrous stroma seen. In view of typical clinical history and cytology, a diagnosis of a crystallizing galactocele was rendered.

Discussion

Although most of the palpable breast lesions in the pregnant and lactating females are benign, but they require prompt attention because 3% of the breast cancers are diagnosed in this population [4]. They may either have a galactocele, a benign adenoma, or a carcinoma [1]. A galactocele is an uncommon benign cystic lesion of the breast containing inspissated collection of milk products [2]. Galactocele develops due to the obstruction of mammary duct in the lactating breast, most likely due to inflammation or in rare cases by a tumor. It is most commonly located in sub-areolar region and can be associated with several breast lesions which result in a ductal obstruction such as Oral contraceptive pills, breast surgery, transplacental passage of prolactin etc [4].

FNAC is usually a cost effective, diagnostic procedure for the evaluation of most of the palpable breast lumps found during pregnancy and in the post-partum period [4]. Sometimes FNAC is unsuccessful to yield as protein plug may remain intact but milk production continues. Galactocele are sterile collection of milk, as outlet is not there to become contaminated. The crystal formation in this condition occurs because of precipitation of inspissated milk secretion [1,2]. Various types of proteins aggregate, carbohydrates and minerals are present in milk. Supersaturation of these milk substances under acidic environment leads to formation of calcium lactate or tyrosine crystals [5]. These crystals are usually composed of calcium, potassium, chlorine and Sulphur [2]. Till date only five case reports of the cytological features of a Crystallizing galactocele are available in medical literature. Our case report is the sixth case of this rare entity (Table 1).

Raso et al. reported first case in 1997 in a 23 year old female and came to conclusion that a diagnosis of crystallizing galactocele should be considered whenever a milky, viscous fluid is aspirated from the breast mass of a pregnant or lactating female [2]. The metachromatic crystals were periodic acid-Schiff positive as well as show positivity for calcium stains. Nikumbh et al. reported second case in 2013 in a 27 years old female in which thick, milky material was aspirated from breast mass with reduction in the size of lump [4]. Jyothi et al. reported third case in a 30 year old lactating female with aspiration of chalky white material from the breast lesion, while the fourth case was reported by Nuzhat et al. in a 35 year old female with aspiration of chalky white material on FNAC with obstruction of the needle with aspirated material [1,3]. Shetty et al. reported fifth case of crystallizing galactocele in a 25 years old lactating woman who presented with slow growing painless lump in upper outer quadrant of her right breast. They categorize these crystals as of tyrosine crystals, similar to those seen in urine cytology, which was further confirmed by using polarizing microscope [5].

Radiologically it could be confused with breast abscess and carcinoma. Clinically Lactating adenoma and fibroadenoma come under differential diagnosis of this condition [1]. Diagnosis of a galactocele is often challenging to make on sonography alone, hence a pathologic diagnosis is often warranted. The crystals in the these case represented precipitated lactational secretions [2].

Conclusion

To conclude, the diagnosis of crystallizing galactocele should be considered whenever milky, viscous, chalky material is aspirated on FNAC from the breast lump of lactating or pregnant female with reduction in the size of the lump. We report this case due to the unusual features of the galactocele, which was diagnosed on FNAC as a crystallizing galactocele as well as due to rarity of this condition.