Rapid progression and unusual premortal diagnosis of mucormycosis in patients with hematologic malignancies: analysis of eight patients

Case report: A rare case of pulmonary mucormycosis caused by Lichtheimia ramosa in pediatric acute lymphoblastic leukemia and review of Lichtheimia infections in leukemia

Mucormycosis caused by Lichtheimia ramosa is an emerging and uncommon opportunistic infection in patients with hematological malignancies, with high mortality rates. Herein, we first report a case of pulmonary mucormycosis with Lichtheimia ramosa in a 3-year-old girl recently diagnosed with B-cell acute lymphoblastic leukemia. The diagnosis was made using computerized tomography of the lung, metagenomic next-generation sequencing (mNGS) of blood and sputum specimens, and microscopic examination to detect the development of Lichtheimia ramosa on the surgical specimen. She was effectively treated after receiving prompt treatment with amphotericin B and posaconazole, followed by aggressive surgical debridement. In our case, the fungal isolates were identified as Lichtheimia ramosa using mNGS, which assisted clinicians in quickly and accurately diagnosing and initiating early intensive treatment. This case also indicated the importance of strong clinical suspicion, as well as aggressive antifungal therapy combined with surgical debridement of affected tissues.

[Mucormycosis in patients with hematological diseases: seven cases reports and literature review]

目的

探讨血液病合并毛霉菌病患者的临床特征、诊治与转归，提高对该病的认识。

方法

回顾性分析2012年9月至2018年9月7例血液病合并毛霉菌病患者的临床资料，分析其临床特征、治疗过程和转归。

结果

7例血液病合并毛霉菌病患者中，男4例，女3例，中位年龄36（19~79）岁。基础疾病：急性髓系白血病2例，急性B淋巴细胞白血病、外周T细胞淋巴瘤、慢性髓性白血病急髓变、骨髓增殖性肿瘤及重型再生障碍性贫血（移植后）各1例。毛霉菌病临床类型：4例为肺型，1例为鼻眶脑型，1例为皮肤型，1例为播散型。7例患者均通过活检组织病理确诊。治疗药物为两性霉素B、两性霉素B脂质体及泊沙康唑。手术治疗4例，其中3例术中彻底清除病变组织，1例仅行局限性清除。治愈2例，好转1例，死亡4例。

结论

血液病合并毛霉菌病患者临床表现及影像学表现多样，死亡率高，确诊主要依赖于组织病理学。早期诊断、控制基础疾病、改善免疫抑制状态、尽早行有效的抗真菌药物治疗及彻底的手术清创治疗是提高血液病合并毛霉菌病患者生存率的关键。

Successful Treatment of Intestinal Mycosis Caused by a Simultaneous Infection with Lichtheimia ramosa and Aspergillus calidoustus

A 53-year-old woman was hospitalized due to septic shock after developing pneumococcal pneumonia after undergoing esophageal cancer surgery. Her transverse colon became perforated after receiving antimicrobial chemotherapy; therefore, emergency subtotal colectomy was performed. Fungi detected in both her colon tissue and a drainage sample indicated intestinal mucormycosis. Early intensive treatment with high-dose liposomal amphotericin B was successful, and she was subsequently discharged from the hospital. The fungal isolates were identified to be Lichtheimia ramosa and Aspergillus calidoustus via gene sequencing using panfungal primers as well as species-specific primers against elongation factor 1 and beta-tubulin for detecting Lichtheimia and Aspergillus, respectively.

Management of Pulmonary Mucormycosis Based on a Polymerase Chain Reaction (PCR) Diagnosis in Patients with Hematologic Malignancies: A Report of Four Cases

Pulmonary mucormycosis (PM) is a life-threatening fungal infection in patients with hematologic malignancies, and early and accurate diagnostic modalities are urgently needed. We conducted a polymerase chain reaction (PCR) assay targeting these fungi in peripheral blood from four patients with hematologic malignancies who were strongly suspected of having PM. In these four patients, the Rhizopus species was identified in two patients, and the Cunninghamella and Absidia species in one each. Based on these molecular findings, all of the patients were successfully treated via targeted therapy with liposomal amphotericin B. In this report, a PCR analysis proved very useful for managing PM in patients with hematologic malignancies.