Gynecomastia caused by ethionamide

A 43 year old male patient, known case of multidrug resistant tuberculosis, was prescribed antitubercular drugs: kanamycin, levofloxacin, ethionamide, terizidone, Para-Aminosalicylate Sodium (PAS), pyrazinamide and pyridoxine. After 4 months of treatment, the patient developed a lump in the right breast which was approximately around 3 × 3 cm in size, tender on palpation, and not fixed to the underlying tissues. Ultrasonography (USG) revealed a hypoechoic mass of size 2.5 × 0.92 × 2.6 cm in the right breast region behind the nipple without any infiltration to the deeper structures. Gynecomastia due to ethionamide was suspected and the patient was advised anti-inflammatory drugs for 5 days without any change in drug therapy. The pain subsided; however, the nodule remained. Treatment was continued without any change till the patient stopped using the drugs on his own and without doctor's consent. Within a week of stopping of treatment the nodule also disappeared.