History and exam

Key diagnostic factors

common

presence of risk factors

Specific risk factors for HCL have not been established. However, the disease tends to occur more often in white people, in men, and in people aged >50 years.[3][5][6][7]

abdominal fullness or discomfort

Typically attributed to an enlarged spleen; may be palpable.

splenomegaly

Splenomegaly is a common physical finding.[7][36][37]

Other diagnostic factors

common

weakness and fatigue

Patients may present with fatigue or lethargy.[7][35]

unexplained weight loss

Some patients may present with weight loss.​[35]

bruising and bleeding

Patients may report gingival bleeding, epistaxis, and easy bruising (due to thrombocytopenia).[33]​[35]​ Petechiae may be present.

Less commonly, skin lesions can be due to vasculitis related to infiltration of the vessel wall by hairy cells.[39]

pallor

Pallor is a common finding during physical examination.[36][37]

recurrent infections

Patients may present with recurrent infections due to neutropenia and monocytopenia (e.g., Mycobacterium kansaii, Pneumocystis jirovecii, Aspergillus, Histoplasma, Cryptococcus, and Toxoplasma gondii).​[35]

hepatomegaly

Hepatomegaly is present in 40% to 50% of patients.[7][36][37]

uncommon

lymphadenopathy

Lymphadenopathy is present in approximately 10% of patients (on occasion with peripheral nodes >2 cm in diameter).[7][38]

Computed tomography (CT) can detect internal adenopathy in approximately 15% of patients.[48]

neurological findings

Neurological disorders (e.g., Guillain-Barre, signs of meningitis, and nerve compression) are reported in rare cases of HCL, but infection cannot not be ruled out as a cause in these reports.[40]

associated systemic immunological disorders

HCL may manifest as a variety of immune dysfunctions (e.g., polyarteritis nodosa, pyoderma gangrenosum, scleroderma, polymyositis, and erythematous maculopapules), but this is uncommon.[41]

Risk factors

strong

middle age

Median age at diagnosis has variously been reported as 55-67 years.[4][5][6][7]​​​[8]

male sex

HCL is more common in males (male:female incidence rate ratio of 2.77 [2011-2012 US data]).[3]

Occupational exposures (e.g., farming, industrial, engineering) may contribute to sex differences.[5][9][10]​​[11][12]

white ancestry

In the US, incidence of HCL is highest among non-Hispanic white people (0.5 per 100,000, age adjusted to the US standard population), followed by non-Hispanic black people (0.3 per 100,000), Hispanic people (0.3 per 100,000), and Asian/Pacific Islanders (0.2 per 100,000).[3]

western hemisphere location

HCL appears to occur more commonly in the western hemisphere (e.g., US, UK) than other regions (e.g., Japan, Africa), although accurate epidemiological data for other regions are lacking.[13][14]

weak

environmental exposures

Exposure to benzene, organophosphorous insecticides, radiation, agricultural chemicals, or wood dust.[9][5][11][12][15][16][18]

Occupational exposures (e.g., farming, industrial, engineering) may contribute to sex differences.[5][9][10]​​[11][12]

genetic predisposition

A number of familial cases have been described.[19][20][21]

Epstein-Barr virus

Epstein-Barr virus infection may have a pathogenic role in HCL.[15][17]

infectious mononucleosis

Previous history of infectious mononucleosis may be associated with the occurrence of HCL.[15]

Use of this content is subject to our disclaimer