Hairy cell leukemia (HCL) is a rare disease of mature B-cell neoplasms. Its name comes from the hair-like strands surrounding the cytoplasm of the cells, which are observed on peripheral blood or bone marrow smears. Leukemic cells mainly involve the spleen, peripheral blood, and bone marrow. The classical immunophenotyping of HCL includes overexpression of the B-cell surface antigens such as CD19, CD20, and CD22 and co-expression of CD25, CD103, CD11c, and CD123. Other markers including CD5, CD10, and CD38 are usually negative, in which CD38 is considered a poor prognostic factor. Herein, we report a case of HCL with atypical morphology and abnormal expression of both CD38 and CD10.

CD38 is a glycoprotein that is highly and uniformly expressed in plasma cells in multiple myeloma. A panel of CD38 and CD138/CD19/CD45/CD56/CD117 markers is considered the immunophenotypic diagnosis of plasma cell myeloma. Expression of the CD38 marker may fade or weaken compared with the CD138 marker in plasma cells after chemotherapy treatment. Herein we present a rare case of CD38-negative multiple myeloma that was initially misdiagnosed as acute leukemia.

T-cell large granular lymphocytic leukemia (T-LGL leukemia) is a rare, chronic lymphoproliferative disorder in the peripheral blood. This is characterized by peripheral blood and bone marrow (BM) lymphocytic infiltration with clonal large granular lymphocytes (LGLs). The neoplastic cells of this disease display a mature T-cell immunophenotype, with the majority of cases showing a CD4-/CD8+ T-cell, T-cell receptor (TCR) subset immunophenotype versus other permutations of those markers.

Background: Acute myeloid leukemia (AML) has the proliferation of poorly differentiated immature myeloid cells. New studies on immune markers also consider them as one of the factors that affect the prognosis or the patient's ability to respond to drugs. Our study was designed to determine the rate of remission and mortality, and the ability to respond to drugs in newly diagnosed AML patients with positive CD81. Methods: A total of 50 patients diagnosed with AML (excluding acute promyelocytic leukemia) underwent immunophenotyping analysis using flow cytometry. Following the initial diagnosis, the patients received induction therapy, followed by three cycles of consolidation therapy. The patients were then followed up for a period of six months. The treatment efficacy was assessed at two timepoints: on day 28 after the first chemotherapy course and on day 28 after the fourth chemotherapy course. Results: Out of the 50 newly diagnosed AML patients, 40 (80%) were found to be CD81 positive. This CD81-positive group had a high mortality rate after the first course of chemotherapy (17.5%) and after the fourth course of chemotherapy (52.5%), while no patients died in the CD81-negative group. The CD81-positive group had a worse drug response rate with 22.5% and 18.2% in CD81 positive group versus 30% and 40% in the CD81-negative group achieving complete remission after the first course and fourth course, respectively. Conclusions: The CD81 immunological marker was found to be highly prevalent among AML patients in Vietnam. Overexpression of CD81 in patients with AML is associated with an unfavorable prognosis, characterized by higher mortality rates and poorer treatment response.

Morphology and immunohistochemistry on node, tissue, and bone marrow biopsies are frequently used in lymphoma diagnosis to characterize the stage and subtype of diseases. Multicolor flow cytometry technology is a novel technique for the analysis of immunological markers to identify lymphoma on fresh tissue when immunohistochemical staining is ambiguous. We report a case of a patient diagnosed with diffuse large B-cell lymphoma by flow cytometry on a stomach tissue biopsy.

Coxiella burnetii is an obligate intracellular bacterium that causes the zoonotic infectious disease, Q fever. The common clinical presentation is fever, hepatitis, and pneumonia; laboratory examination could reveal pancytopenia, elevated liver enzymes. In bone marrow, many fibrin ring granulomas, also known as “Doughnut” granulomas can be seen and suggest the diagnosis of Q fever. However, these bone marrow granulomas can also be presented in infectious diseases by other pathogens such as EBV, CMV, and HBV; therefore, other serology or PCR—based tests are needed to confirm the diagnosis of Q fever. We report the first case of acute Q fever in Vietnam, presented as a fever of unknown origin with hepatitis in a 53-year-old male patient. A bone marrow biopsy was performed and showed various fibrin ring granulomas; therefore, Coxiella was suspected and the diagnosis was confirmed by PCR. Some infectious diseases can cause specific changes in the bone marrow, such as Doughnut granulomas in Q fever. These features can help direct the diagnosis and decide earlier treatment for the patient.

Histoplasmosis is an endemic infection caused by Histoplasma capsulatum, leading to a broad spectrum of disease from asymptomatic to severe disseminated disease. To diagnose Histoplasmosis, culture remains the gold standard for the laboratory diagnosis; however, this fungus grows slowly, taking a long time 2 to 3 weeks or may take up to 8 weeks. Therefore, some other methods such as bone marrow examination play an essential role in rapid identification and early diagnosis, especially in cases of severe disseminated disease. In this case, we report a 55-year-old man with a 1-year history of gout, self-medicating (including Medrol) who was admitted to the hospital because of persistent fever and swelling of his left arm. About laboratory investigation, there was a bicytopenia (RBC and PLT), blood and pus cultures many times were negative. On the slide of the bone marrow specimen, images of yeast suspected of Histoplasma capsulatum were observed. Therefore, the patient was treated with antifungal medication, and the culture was repeated with prolonged follow-up time and positive results with H. capsulatum after 16 days. In conclusion, bone marrow test plays a significant role in the diagnosis of some fungal infections, which can contribute to an early diagnosis, especially in cases of culture and serological tests are not available or cannot be performed. Patients who present with fever and bicytopenia or pancytopenia should be performed early bone marrow test, which can support the earlier diagnosis to have appropriate treatment.