Histoplasmosis is a systemic mycosis caused by the dimorphic fungus in the genus Histoplasma. Histoplasmosis is overlooked in China. This study aims to provide an epidemiological and clinical update on histoplasmosis in China by literature review. We reviewed cases of histoplasmosis reported in recent 11 years and described a case of histoplasmosis-triggered hemophagocytic lymphohistiocytosis (HLH) in an immunocompetent patient. A total of 225 cases of histoplasmosis diagnosed in China between 2012 and 2022 were involved in this study, compared with 300 cases reviewed from 1990 to 2011, an increasing number of cases of histoplasmosis have been diagnosed in the last 11 years. The majority of cases of histoplasmosis were autochthonous cases, mainly from provinces Sichuan (56/225, 24.9%), Hunan (50/225, 22.2%), Guangdong (31/225, 13.8%), and Yunnan (24/225, 10.7%). Higher incidence (52.5%, 53/99) of histoplasmosis occurred in immunocompetent patients which is similar to those from the previous 21 years, and the prevalence of the disease did not vary highly over time. Of note, the number of histoplasmosis cases is increasing, and the geographic distribution is shifting southwards over time. Improved awareness is critically important for informing clinical practice in China.

Minimal residual disease (MRD) is one of the most relevant prognostic factors in patients with multiple myeloma (MM). However, the hemodilution of bone marrow (BM) aspirates, the most common preanalytical problem, is known to affect MRD detection. In the present study, we analyzed a preanalytical method for routine BM aspirates and a bone marrow particle cell (BMPL) enrichment assay and validated it as a reliable preanalytical method for flow cytometric MRD determination. A total of 120 BM samples were taken from 103 MM patients consecutively recruited; 77 BM samples had BMPL enrichment analysis and 99 BM samples were routinely analyzed. Then, the two different samples from patients with MM were sent for MRD detection using an eight-color flow cytometry. Our data showed that assessment of the BMPL enrichment samples attenuated the overestimation of MRD-negative assessed in the routine BM samples, which was mainly caused by hemodilution. In conclusion, the BMPL enrichment assay is a functional and practical preanalytical method for flow cytometric MRD analysis.

Bone marrow smear and biopsy are the main methods for the diagnosis of multiple myeloma (MM), bone marrow infiltration, and metastasis in lymphoma and cancer. However, several factors, including the focal growth of tumor cells, inappropriate puncture sites, and hemodilution of bone marrow aspirates, lower the rate of target cell detection. To solve this problem, we developed a novel method—bone marrow particle enrichment analysis—and here, we describe this procedure and its use in the diagnosis of a rare case of MM.