Multiple brain lesions in a patient with relapsed hairy cell leukemia: a case report and review of the literature

A diagnostic dilemma: Atypical melanocytic lesions arising in the setting of treatment with the BRAF inhibitor, vemurafenib

Multiple cystic brain lesions in a patient with pilocytic astrocytoma

Chemotherapy

BRAFV600E Mutations Occur In The Hematopoietic Stem Cell Compartment In Hairy Cell Leukemia

Hairy cell leukemia (HCL) is a rare and indolent mature B cell neoplasm. Most patients with HCL have excellent response to purine analogs and BRAF inhibitors. Therefore, it is clinically important to identify and differentiate HCL from other B cell neoplasms. HCL is predominantly found in the peripheral blood, bone marrow, or spleen. HCL presenting initially or solely in unusual sites is extremely rare (approximately ten or fewer). We hereby report a unique case of HCL presenting as vertebral osteolytic and epidural mass lesions without bone marrow, spleen, or peripheral blood involvement. The patient was a 53-year-old male with acute and chronic radicular pain down the posterior aspect of bilateral thighs. Imaging study with MRI demonstrated a L4 posterior vertebral osteolytic mass lesion, extending into the spinal canal, and a second right sacral S1 lesion extending into the sacral iliac joint. These two noncontiguous lesions were thought to be consistent with metastatic cancer or sarcoma, and the specimen was submitted to non-hematopoietic pathologist for diagnosis without flow cytometry. Initial immunohistochemical stains were ordered for solid tumor markers, which were all negative. As part of the workup, immunostain for BRAF V600E (VE1) was ordered for melanoma, and CD138 and cyclin D1 for myeloma, which returned positive and suggested the possibility of hairy cell leukemia. Additional workup for hairy cell leukemia confirmed the diagnosis. HCL typically presents with peripheral blood, bone marrow, or spleen involvement, while mass lesions in other sites are rare. High index of suspicion is essential for the correct diagnosis of HCL in mass lesions at unusual sites. In the absence of initial hematopathological workup and flow cytometry, HCL presenting as solid mass in unusual locations is misdiagnosed most likely as marginal zone B cell lymphoma (mucosa-associated lymphoid tissue (MALT) lymphoma). The expression of cyclin D1, TRAP, annexin A1, and BRAF V600E mutation would confirm the diagnosis of HCL. The main differentials include MALT lymphoma, mantle cell lymphoma (MCL), and hairy cell leukemia variant (HCLv). This case report will be interesting for the clinicians and pathologists alike and broaden the spectrum of clinical presentation of lymphomatous HCL.

Importance of FDG-PET (Fluorodeoxyglucose Positron Emission Tomography) in Staging and Response Assessment of Hairy Cell Leukemia (HCL)

Prolonged, Complete Remission After 2-Chlorodeoxyadenosine Therapy in a Patient With Refractory Essential Mixed Cryoglobulinemia

Hairy Cell Leukemia with Severe Leukocytosis

Angiomyomatous hamartoma of the inguinal lymph nodes with localized lymphedema presenting as a soft subcutaneous mass

New Generation Sequencing of Targeted Genes in Hairy Cell Leukemia Highlighted Mutations Associated to BRAFV600E anda New Recurrent Altered Gene, KDM6A, in Hairy Cell Leukemia Variant Patients

Frequent T and B Cell Oligoclones in Histologically and Immunophenotypically Characterized Angioimmunoblastic Lymphadenopathy

Objective: To investigate the role of a patent foramen ovale in the pathogenesis of multiple brain lesions acquired by sport divers in the absence of reported decompression symptoms.Design: Prospective double...

The overall survival of patients with hairy cell leukemia (HCL) has significantly increased in recent years because of the development of effective treatments such as interferon alpha and purine analogs. Several reports have described an increased risk of secondary cancers, particularly solid tumors, in patients with HCL. We describe a case of a patient with HCL, who had prolonged pancytopenia after a single course of cladribine. Fifteen months after the diagnosis of HCL the patient developed acute myeloid leukemia (AML) and died shortly afterwards. Review of the literature shows few reports of acute leukemia in HCL patients. All of the 11 reported cases of leukemia in patients with HCL have been in patients who have been treated with either interferon alpha or purine analogs, and developed several years (mean 4.3 years; range 1.6-6.4 years) after the diagnosis of HCL. Our case is unusual in that the patient developed AML shortly (1.2 years) after the diagnosis and treatment of HCL. Further studies are needed to clarify whether leukemias seen in patients following the treatment of their HCL are incidental findings or related to HCL and its treatments.

Unusual esophageal injury after atrial fibrillation ablation: Early diagnosis and treatment to optimize outcomes

Long-Term Treatment of Hairy Cell Leukemia Patients with Interferon: Clinical and Molecular Aspects