Hairy Cell Leukemia Presenting with Isolated Skeletal Involvement Successfully Treated by Radiation Therapy and Cladribine: A Case Report and Review of the Literature

Abstract

We describe an unusual case of hairy cell leukemia (HCL) in a 55-year-old male presenting with isolated skeletal disease as the initial manifestation without abnormal peripheral blood counts, bone marrow involvement, or splenomegaly. To the best of our knowledge, there have been only two previous reports of a similar case. The patient presented with pain in the right femur. Anteroposterior radiographs of both femurs revealed mixed lytic-sclerotic lesions. PET scan showed multiple metastatic lesions on axial skeleton, pelvis, and both femurs. Histopathological examination of the bone biopsy revealed an infiltrate of HCL. Localized radiation therapy to both proximal femurs and subsequently 4 weeks later, a 7-day course of 0.1 mg/kg/day cladribine provided complete remission with relief of symptoms and resolution of bone lesions. We addressed the manifestations and management of HCL patients with skeletal involvement.

Bone lesions in hairy cell leukemia: Diagnosis and treatment

“…The longest time between HCL diagnosis and bone involvement was 22 years. 20 Following the introduction of very effective systemic therapy with PNA, skeletal localizations appear to be encountered less frequently, probably due to the protective benefits of successful frontline treatment. 11…”

“…18 Diffuse demineralization of the bone has been described in approximately 15% of cases; occasionally, extensive osteoporosis and aseptic necrosis of the femoral or humeral head have also been observed. 20 In most cases, cortical bone destruction or periosteal reaction was not reported. However, abnormal bone remodeling and increased bone resorption has been also noted.…”

Atypical presentation of hairy cell leukemia: a report and comprehensive review

“…Atypical or unusual presentation in HCL (aHCL) is uncommonly reported in the literature (1990 to 2018), which may pose a significant diagnostic challenge in routine practice (Table 1) [2][3][4][5][6][7][8][9][10]. Splenohepatomegaly is conspicuously absent which, in the presence of peripheral blood cytopenia(s), resembled hypoplastic anemias.…”

“…Splenohepatomegaly is conspicuously absent which, in the presence of peripheral blood cytopenia(s), resembled hypoplastic anemias. Significant lymphadenopathy; skeletal manifestation in the form of arthralgia, multifocal lytic to sclerotic bone lesions; neurological manifestations; isolated epidural, skull base, or breast lesions have dominated the clinical presentations in other reports [2,[4][5][6][7][8][9]. HCs were conspicuously absent to very sparse; both in peripheral blood smear (PBS) and scant bone marrow aspirate (BMA) smears requiring tartrate-resistant acid phosphatase (TRAP) cytochemistry.…”

Skeletal involvement of hairy cell leukemia

“…Treatment relies on purine analogs with remarkable response rates. Skeletal involvement is an unusual manifestation of HCL, complicating the course of the disease in approximately 3% of patients and rarely observed at presentation . The lesions, mainly osteolytic and painful, are preferentially distributed in the axial skeleton and proximal long bones, but very few cases of skull involvement have been reported.…”