Bone lesions in hairy cell leukemia: Diagnosis and treatment

Abstract

Hairy cell leukemia (HCL) is a rare and indolent form of small mature B-cell leukemias. The annual incidence of HCL is estimated to be 0.3 cases per 100 000, and the disease comprises 2%-3% of all leukemias. 1,2 It was estimated that 1100 new cases of HCL and 4060 deaths occurred in 2016 in the USA. 3,4 It is mostly a disease of middle-aged males (median age 55 years and 4:1 male predominance). Patients present most frequently with splenomegaly, pancytopenia, and bone marrow infiltration. Hairy cells characteristically stain strongly positive for tartrate-resistant acid phosphatase (TRAP) and have a typical pattern of B-cell antigen expression (CD19, CD20) with co-expression of CD11c, CD25, and CD103. Cell surface markers associated with normal B-cell activation, especially CD22, CD72, and CD40, are also strongly expressed. 3,4 The BRAF V600E mutation is present in all patients and is regarded as a disease-defining genetic event. 5 Purine nucleoside analogs (PNA), cladribine (2-CDA), and pentostatin (DCF, deoxycoformycin) are the drugs of choice in first-line treatment of HCL 3,4 ; they induce durable and unmaintained complete response (CR) in more than 70% of patients, with relapse rates of 30%-40%, after 5-to 10-year follow-up. However, despite very high initial response rates, many patients ultimately relapse or develop refractory disease and will require novel therapies after these agents. 3 Unusual clinical manifestations of HCL are occasionally reported. 6-14 These rare symptoms may include bulky abdominal lymphadenopathy, tumor masses in the mediastinum, paravertebral masses,

Hairy cell leukemia 2022: Update on diagnosis, risk‐stratification, and treatment

“…At diagnosis, HCL is usually characterized by infections, splenomegaly, or the presence of cytopenias. Autoimmune or unusual clinical manifestations are occasionally reported as bulky abdominal lymph nodes, pleural effusions and ascites, skin lesions 14 or destructive bone lesions some of which can mimic multiple myeloma 15,16 . With the high frequency of routine peripheral blood analyses, hairy cells can also be detected in asymptomatic patients.…”

“…Autoimmune or unusual clinical manifestations are occasionally reported as bulky abdominal lymph nodes, pleural effusions and ascites, skin lesions 14 or destructive bone lesions some of which can mimic multiple myeloma. 15,16 With the high frequency of routine peripheral blood analyses, hairy cells can also be detected in asymptomatic patients. Complete blood count and careful review of the peripheral blood smear are the first step in the very characteristic morphological identification of hairy cells (Figure 1A).…”

Diagnosis and treatment of hairy cell leukemia as the COVID-19 pandemic continues

“…The skin is involved in 10–12% of patients with HCL, usually due to autoimmune or infectious etiologies, and direct leukemic involvement of the skin (leukemia cutis) is much rarer [ 38 ]. Bone lesions have also been recognized as a feature of HCL [ [39] , [40] , [41] ]. Pulmonary abnormalities are usually due to infections or adenopathy, but leukemic involvement of the lungs was reported in 2 of 21 autopsied patients [ 42 ].…”

Hairy Cell Leukemia

“…If symptomatic, they typically present with symptoms related to worsening pancytopenia (fatigue, bruising, gingival bleeding, epistaxis, menorrhagia), splenomegaly (abdominal fullness, discomfort growing after eating) and recurrent infections. Rare clinical manifestations include polyarteritis nodosa, cutaneous leukocytoclastic vasculitis, bone involvement or central nervous system involvement (22,23).…”