不规则毛霉致原发性皮肤毛霉病一例

Cutaneous mucormycosis caused by Mucor irregularis： a case report

患者女，39岁，右面部斑块、溃疡伴疼痛2个月。既往患急性髓系白血病1年，经治疗后缓解，半年前再次复发。皮肤科检查：右面颊5 cm × 5 cm紫红色斑块，中央糜烂溃疡，表面覆盖黄褐色痂皮，可见肉芽组织，剥去痂皮有黄色脓液溢出，皮损边界清晰，边缘稍隆起，触痛明显。实验室检查：白细胞28.75 × 109/L，中性粒细胞1.05 × 10^9/L，淋巴细胞27.17 × 10^9/L，红细胞2.20 × 10^12/L，血红蛋白69 g/L，血小板84 × 10^9/L；肝肾功能、电解质及心电图检查未见异常。皮损组织病理HE及过碘酸希夫染色示真皮内大量淋巴细胞及组织细胞浸润，并见宽大无隔菌丝。真菌小培养见宽大透明无隔菌丝，并见假根、匍匐菌丝及球形孢子囊。分子生物学鉴定为不规则毛霉。诊断：①不规则毛霉致原发性皮肤毛霉病；②急性髓系白血病。给予口服羟基脲（0.5 g每日3次）、一次性静脉输注悬浮红细胞（4个单位），静脉滴注两性霉素B（起始剂量5 mg/d，每天递增5 mg，最大增至25 mg/d，约0.5 mg·kg^-1·d^-1），患者皮损逐渐变平、缩小。12 d后因故患者出院后失访。

A 39-year-old female patient presented with a painful plaque with ulcers on the right cheek for 2 months. She had acute myeloid leukemia for 1 year. After treatment, the patient achieved remission, but experienced recurrence half a year prior to the presentation. Skin examination showed a violaceous plaque measuring 5 cm × 5 cm in size on the right cheek with erosions and ulcers in the center, whose surface was covered with yellowish brown crusts. Granulation tissues were observed on the plaque, and yellow pus was exuded after the crusts were removed. The boundary of the plaque was sharp and slightly elevated, and there was obvious tenderness on palpation. Laboratory examination revealed increased white blood cell （WBC, 28.75 × 109/L） and lymphocyte counts （27.17 × 109/L）, but decreased neutrophil （1.05 × 109/L） and red blood cell counts （2.20 × 1012/L）, hemoglobin level （69 g/L） and platelet count （84 × 109/L） in the peripheral blood. The hepatic and renal function, electrolyte level and electrocardiogram were normal. Hematoxylin and eosin （HE） staining and periodic acid-Schiff staining of the lesion showed a large number of lymphocytes and histiocytes infiltrating in the dermis and broad aseptate hyphae. The fungal microculture yielded broad hyalinea septate hyphae, fungal rhizoids, stolons and spherical sporangia. The isolated fungus was identified as Mucor irregularis by using molecular biology techniques. The patient was diagnosed with primary cutaneous mucormycosis caused by Mucor irregularis complicated by acute myeloid leukemia. Then, the patient was treated with oral hydroxyurea at a dose of 0.5 g thrice a day, a single-dose intravenous infusion of 4 units of red blood cell suspension, and intravenous drip infusion of amphotericin B at an initial dose of 5 mg/d, which increased by 5 mg every day until 25 mg/d （about 0.5 mg·kg-1·d-1）. After the treatment, the lesion gradually became flat and smaller. After 12-day treatment, the patient was discharged because of a certain reason, and finally lost to follow-up.