1例19岁女性患者因精神分裂症服用利培酮3 mg、2次/d，服药前无乳头溢液史，服药后间断出现乳头溢液。服药1年后发现右侧乳房（右乳）肿物伴疼痛，经乳癖散结胶囊、头孢地尼、布洛芬、利福平及异烟肼治疗不能缓解，肿物继续增大并出现双侧膝关节疼痛、双下肢结节红斑伴触痛。实验室检查：血白细胞计数18.4×10n 9/L，血清催乳素37.42 μg/L。乳腺超声示右乳可见范围约13.2 cm×11.0 cm×3.0 cm偏低回声，形态欠规则，边界不清，局部有流动性，周边可见丰富血流信号。诊断为右乳肉芽肿性小叶性乳腺炎（脓肿期），高催乳素血症。排除生理和病理等原因后，考虑为利培酮导致高催乳素血症诱发肉芽肿性乳腺炎。但未经专科医师指导不能停用利培酮，仅予脓肿切开引流+清创术、抗感染、抗炎等治疗。脓性分泌物逐渐减少，疼痛减轻，下肢部分红斑消退。患者在精神科医师指导下调整利培酮剂量为2 mg、2次/d，血清催乳素降低（28.36 μg/L）。随访1年，肉芽肿性乳腺炎未复发。n “,”A 19-year-old female patient received risperidone 3 mg twice daily for schizophrenia. She did not have nipple discharge before taking the drug. After taking the drug, nipple discharge occurred intermittently. One year later, a mass with pain in the right breast was found, which could not be alleviated after treatments with n Rupi Sanjie capsules (乳癖散结胶囊), cefdinir, ibuprofen, rifampicin, and isoniazid and continued to increase, accompanied by bilateral knee pain, nodular erythema and tenderness of lower limbs. Laboratory tests showed white blood cell count 18.4×10n 9/L and serum prolactin 37.42 μg/L. Ultrasonography of the right breast showed a 13.2 cm×11.0 cm×3.0 cm area low echo with unclear boundary, local fluidity, and abundant blood flow signals around. Granulomatous lobular mastitis of right breast (abscess stage) and hyperprolactiemia was diagnosed. After excluding physiological and pathological reasons, it was considered that risperidone caused hyperprolactinemia, which then induced granulomatous mastitis. However, risperidone could not be stopped without the guidance of a specialist, so only abscess incision, drainage, debridement, anti-infection, and anti-inflammatory were given. Purulent secretions gradually decreased, pain alleviated, and erythema of lower limbs partially subsided. Then risperidone dose was adjusted to 2 mg twice daily under the guidance of her psychiatrist. The serum prolactin level decreased (28.36 μg/L). At 1 year of follow-up, granulomatous mastitis did not recur.n