Subcutaneous Cryptococcosis Mimicking Cold Abscess

Abstract

Cryptococcosis is a fungal infection caused by the yeast belonging to the Cryptococcus species which includes broadly two categories Cryptococcus neoformans and Cryptococcus gattii. It most commonly affects the lungs and central nervous system, particularly in immunocompromised patients. Other sites of dissemination include skin, ends of long bones, joints, liver, spleen, kidneys, prostate and other tissues. A 32-year-old male patient came to surgical OPD with complaints of a right posterior thigh swelling extending up to knee measuring approximately 8x6 cm. There was a past history of receiving Anti-Tubercular Treatment (ATT) for three months but without any improvement in symptoms. MRI of the thigh suggested a possibility of cold abscess or chronic haematoma. Fine Needle Aspiration Cytology (FNAC) of the thigh showed numerous spherical encapsulated yeast cells with only few macrophages in the background. Special stains like Periodic Acid–Schiff (PAS) highlighted the fungus while mucicarmine highlighted the capsule of fungi. Ziehl Neelsen stain for acid fast bacilli was negative. A final cytological diagnosis of cryptococcosis was given which was confirmed by the culture reports. In developing countries like India where there is high incidence of tuberculosis, fungal infection like cryptococcosis is likely to be missed particularly if high index of clinical suspicion for tuberculosis is present.

Keywords

• cytological
• capsule
• immunocompromised
• tuberculosis