Hairy cell leukemia - etiopathogenesis, diagnosis and modern therapeutic approach.

Hairy cell leukemia (HCL) represents 2% of all leukemia cases, with men aged above 55 years being the most affected. The most common symptoms of this type of leukemia include splenomegaly, monocytopenia, and neutropenia. In the basic blood count examination, leukopenia with monocytopenia and granulocytopenia, as well as aplastic anemia and/or thrombocytopenia occur. The mutation of ß-rapidly accelerated fibrosarcoma (BRAF) proto-oncogene, which can be found in nearly 100% of patients, is an important feature of HCL. Immunophenotypic analysis of the HCL cells reveals high expression of B-lineage antigens, including CD19, CD20, and CD22. Additionally, CD11c, CD25, CD103, and CD123 belong to specific markers of HCL. Lactate dehydrogenase activity and ß-2-microglobulin concentration are also important in the patient's assessment. The differential diagnosis between HCL, hairy cell leukemia variant (HCL-V) and splenic marginal zone lymphoma (SMZL) is of first importance. Currently, the main treatment for HCL involves the use of purine analogues, excluding pregnant women, individuals with severe infections, and those with relapsing HCL.

Concomitantly Diagnosed Disseminated M kansasii Infection and Hairy Cell Leukemia With Review of Pathophysiology.

The association between Hairy Cell Leukemia (HCL) and non-tuberculous mycobacterial infections (NTMs) is well described, most notably Mycobacterium kansasii. The exact pathophysiology is not known. We report a case of a 31-year-old male with concomitantly diagnosed HCL and disseminated M kansasii infection who presented with rash, pancytopenia, and bulky axillary lymphadenopathy. The M kansasii was initially diagnosed through use of cell-free DNA detection and confirmed by bone marrow and lymph node cultures. Hairy Cell Leukemia was diagnosed with peripheral flow cytometry and confirmed via the same bone marrow sample. His HCL was put into remission with a single course of cladribine and rituximab chemotherapy; however, his M kansasii infection persisted for 6 months despite aggressive antimicrobial and surgical therapy. It was finally controlled using high-dose rifampin in combination with azithromycin and ethambutol. This case highlights the known link between HCL and M kansasii. Furthermore, it hints at potential causes beyond chemotherapy-induced immunocompromise. Notable possibilities include HCL cells acting as sanctuary sites for M kansasii to evade the immune system, and subclinical M kansasii infections causing NLRP3 inflammasome overactivation to trigger the oncogenic transformation to HCL. More research into the pathophysiologic link between HCL and M kansasii infections would allow for more effective prevention, diagnosis, and treatment of these severe atypical infections which are the major cause of morbidity in the cladribine era of HCL treatment.

Real-world data on diagnostics, treatment and outcomes of patients with hairy cell leukemia: The HCL-CLLEAR study.

Hairy cell leukemia (HCL) and HCL-like disorders have to be distinguished because of their different biology and treatment response. Thus, we conducted a retrospective study on patients with HCL and hairy cell leukemia variant (HCLv) to assess diagnostic algorithms and treatment outcomes in a real-world setting. We analyzed 225 HCL and 26 HCLv patients with median follow-up of 67.9 months (HCL) and 20.1 months (HCLv). Median age at diagnosis was 56.2 (HCL) and 69.5 years (HCLv), male predominance was observed in both groups (76.0% vs. 73.1%). Diagnostics was mostly based on morphological evidence of hairy cells in the peripheral blood and bone marrow. At diagnosis, BRAF V600E mutation was detected in 94.7% of examined HCL patients and in no HCLv patient. Front-line treatment was indicated in 205 (91.1%) HCL and 18 (69.2%) HCLv patients. The majority of HCL patients were administered a cladribine-based regimen (91.2%). Overall response rate (ORR) was higher in cladribine-treated patients compared to those given other treatments (97.7% vs. 81.3%), the same applied with achieving Complete remission (CR) (91.2% vs. 62.5%). HCLv treatment was heterogeneous, but cladribine remained the most frequent option (44.4%) with ORR 81.3% and CR rates 43.8%. Second-line treatment was indicated in 52 HCL and 8 HCLv patients, 25.4% and 44.4% of those treated in first-line. In the whole HCL group, median time to next treatment (TTNT) was not reached and 10-year TTNT was estimated at 74.1%. HCLv patients who underwent first-line treatment had a median TTNT of 56 months. The median overall survival (OS) in HCL patients was not reached compared to HCLv with a median OS of 9.5 years. These data confirm an excellent prognosis for HCL patients treated with cladribine-based therapy. On the contrary, HCLv with its aggressive behavior represents a group of patients in whom novel treatment approaches are needed.

Splenic B-cell lymphoma/leukemia with prominent nucleoli: A three-case series of the newly named old entity and review of literature.

CONTEXT: Splenic B-cell lymphoma/leukemia with prominent nucleoli (SBLPN) aka hairy cell leukemia variant (HCL-v) is a rare B-cell chronic lymphoproliferative disorder. The main diagnostic challenge is to differentiate SBLPN from Classical hairy cell leukemia (HCL-c), as the former faces inferior responses to therapies and a poor prognosis. AIMS: The aim is to discuss the clinic-hematological and immunophenotyping findings of three cases of SBLPN. SETTINGS AND DESIGN: This is a retrospective observational study. METHODS AND MATERIAL: From the year 2011 to 2021, flow cytometry of all the cases with HCL diagnosis was reviewed, and three cases with negative or dim CD25 and hematological presentation matching with SBLPN were picked up. STATISTICAL ANALYSIS USED: Descriptive statistics is used. RESULTS: All the cases were male. The age ranges from 43 to 64 years. Median hemoglobin concentration, total leucocyte count, and platelet count were 8.6 g/dL, 6.9 × 109/L, and 53 × 109/L, respectively. The atypical cells were medium to large. All three showed prominent nucleoli. Bone marrow biopsies showed an interstitial pattern of infiltration in all the cases. The hairy cells were positive for CD20, CD11c, and CD103. CD25 was dim positive in one case. Annexin A1 was negative in all three cases. BRAF V600E mutation analysis was done in one case and turned out negative for the mutation. CONCLUSIONS: SBLPN is a rare entity, usually on-flow cytometry CD25 negative. However, in dim CD25-positive cases, BRAFV600E mutational analysis helps in discerning SBLPN diagnosis and differentiating it from HCL-c.

Hairy cell leukemia 2024: Update on diagnosis, risk-stratification, and treatment-Annual updates in hematological malignancies.

DISEASE OVERVIEW: Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogenous group of mature lymphoid B-cell disorders characterized by the identification of hairy cells, a specific genetic profile, a different clinical course and the need for appropriate treatment. DIAGNOSIS: Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of 3 or 4 based on the CD11c, CD103, CD123, and CD25 expression, the trephine biopsy which makes it possible to specify the degree of tumoral bone marrow infiltration and the presence of BRAFV600E somatic mutation. RISK STRATIFICATION: Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood, and the immunoglobulin heavy chain variable region gene mutational status. VH4-34 positive HCL cases are associated with a poor prognosis, as well as HCL with TP53 mutations and HCL-V. TREATMENT: Patients should be treated only if HCL is symptomatic. Chemotherapy with risk-adapted therapy purine analogs (PNAs) are indicated in first-line HCL patients. The use of chemo-immunotherapy combining cladribine (CDA) and rituximab (R) represents an increasingly used therapeutic approach. Management of relapsed/refractory disease is based on the use of BRAF inhibitors (BRAFi) plus R, MEK inhibitors (MEKi), recombinant immunoconjugates targeting CD22, Bruton tyrosine kinase inhibitors (BTKi), and Bcl-2 inhibitors (Bcl-2i). However, the optimal sequence of the different treatments remains to be determined.

Discrepant Results for BRAF V600E Mutation Among Different Specimens in a Case of Hairy Cell Leukemia

No abstract available.

Rituximab, 2a línea de tratamiento en leucemia de células vellosas / Rituximab 2nd line of treatment for hairy cell leukemia

La leucemia de células vellosas (LCV) es un desorden linfoproliferativo crónico caracterizado por: esplenomegalia, pancitopenia con linfocitos vellosos e infiltración de médula ósea y de bazo. Rituximab demuestra eficacia terapéutica y en pacientes con LCV refractaria/recaída.

Detection of CD5 in B-cell chronic lymphoproliferative diseases by flow cytometry: a strong expression in B-cell chronic lymphocytic leukemia

OBJETIVOS: CD5 é um marcador normalmente expresso nas células T e de forma aberrante nas células B da leucemia linfocítica crônica (LLC) e no linfoma de células do manto (LCM). Outras doenças linfoproliferativas crônicas como a hairy cell leukemia (HCL) e leukemia prolinfocítica de células B (LPL-B), são geralmente CD5 negativas ou expressam fracamente este antígeno. Neste trabalho investigou-se o padrão de expressão do CD5 em 42 pacientes com doenças linfoproliferativas crônicas de células B (DLC-B). METODOS: Investigamos a expressão de CD5 em células leucêmicas de 42 pacientes com DLC-B através da citometria de fluxo. Dados demográficos, tais como idade e sexo, bem como dados clínicos e laboratoriais também foram analisados. RESULTADOS: A imunofenotipagem mostrou que 35 casos foram LLC, 3 LPL-B, 3 HCL e um caso de LMC. O CD5 mostrou-se fortemente expresso em todos os casos de LLC e LMC. Baixa expressão desse antígeno foi observada em um caso de LPL-B, mostrando-se negativamente expresso em todos os casos de HCL. CONCLUSÃO: Nossos resultados demonstram que o padrão de expressão do CD5 pode auxiliar na distinção entre LLC da HCL e LPL-B, sendo no entanto similares na HCL e LCM.

Vasculitis leucocitoclásicas en leucemias a linfocitos vellosos / Leukocytoclastic vasculitis and hairy cell lymphocystic leukemia

Se presentan tres pacientes en quienes se observa la asociación de leucemia a linfocitos vellosos (LLV) y vasculitis leucocitoclásica (VL) (la vasculitis más frecuente en procesos linfoproliferativos). La LLV es una enfermedad rara que afecta con mayor frecuencia a hombres de edad media, siendo su signosintomatología esplenomegalia, pancitopenia, fatiga, infecciones recurrentes y anemia. Nuestros hallazgos a nivel dermatológico fueron en todos los casos de púrpura palpable. Algunas lesiones se ulceraron y transgredieron los límites inferiores. Se efectúa una revisión de la literatura y se comenta ésta rara asociación. Consultada la bibliografía éstos serían los únicos casos publicados a nivel nacional

Vasculitis leucocitoclásicas en leucemias a linfocitos vellosos / Leukocytoclastic vasculitis and hairy cell lymphocystic leukemia

Se presentan tres pacientes en quienes se observa la asociación de leucemia a linfocitos vellosos (LLV) y vasculitis leucocitoclásica (VL) (la vasculitis más frecuente en procesos linfoproliferativos). La LLV es una enfermedad rara que afecta con mayor frecuencia a hombres de edad media, siendo su signosintomatología esplenomegalia, pancitopenia, fatiga, infecciones recurrentes y anemia. Nuestros hallazgos a nivel dermatológico fueron en todos los casos de púrpura palpable. Algunas lesiones se ulceraron y transgredieron los límites inferiores. Se efectúa una revisión de la literatura y se comenta ésta rara asociación. Consultada la bibliografía éstos serían los únicos casos publicados a nivel nacional (AU)

Tratamento da leucemia de células cabeludas com interferon alfa / Treatment of hairy cell leukemia with alpha interferon

O presente trabalho descreve cinco casos de pacientes portadores de leucemia de células cabeludas (LCC) ou tricoleucemia, que foram tratados com interferon alfa, um modificador da resposta biológica com grande atividade nesta doença crônica linfoproliferativa. Novos conceitos considerando seu uso como terapêutica de primeira linha säo discutidos, bem como aspectos marcantes de sua etiopatogenia, diagnóstico clínico-laboratorial e histopatológico.

Leucemia de células vellosas: complicación dermatológica / Hairy-cell leukaemia: dermatologic complication

Se comunica un paciente de 49 años, sexo masculino, con lesión erosiva impetiginizada en región pubiana y ulceración no infiltrada en prepucio. Masa ganglionar inguinal derecha flegmásica de 15 x 5 x 2,5 cm. Micropoliadenopatías inguinales izquierdas y adenopatía asintomática axilar derecha. Hepatoesplenomegalia. Astenia, Pancitopenia. Los estudios realizados ratificaron el diagnóstico de L. C. V., cuya frecuencia es del 2% en el total de las leucemias del adulto. La C. V. tiene su origen en una célula linfoide B y se sitúa en el sistema de diferenciación en un estadio algo más evolucionado que la de la leucemia linfática crónica. Se caracteriza por tener citoplasma extenso dotado de típicas prolongaciones o pelos. La maior parte del cuadro clínicos es consecuencia de la pancitopenia y la explenomegalia. las lesiones dermatológicas asociadas más frecuentemente son las inespecíficas, y se expresan por infecciones recurrentes, equimosis o las resultantes de vasculitis. Las específicas se observan en un 8% de los casos y se traducen por erupciones máculo-pápulo eritematosas. predomina en el sexo masculino, pero el pronóstico es mejor en el femenino. Los tratamientos instituídos segun la sintomatología y curso evolutivo son la esplenectomía, el alfa Interferón, y 2 - Deoxycoformicina