[Diagnostic value of lymphadenopathy associated with fever and inflammation of unknown origin: a study of 69 patients].

OBJECTIVE

The diagnosis of fever or inflammation of unknown origin (FUO/IUO) is guided by the search of clinical clues. Lymphadenopathy is thought to be helpful but its actual contribution has never been tested, and little is known about the main causes of FUO/IUO with lymphadenopathy. The aim of this study was to clarify these issues from the experience of two departments of internal medicine.

METHODS

We retrospectively studied a cohort of 69 consecutive inpatients with FUO or IUO and lymphadenopathy, hospitalized from January 2002 to February 2008. The patients were coded according to the final diagnosis and age. Recorded data included lymph node location, fever, CRP level, lymphocyte and platelet counts, presence of hyperbasophilic cells, hypogammaglobulinemia, monoclonal gammopathy, LDH level, and the results of histological and or cytological lymph node examination.

RESULTS

Malignancy accounted for 54%, granulomatosis for 23%, mainly of infectious (60%) or malignancy-related origin (18%), the group classified as non-specific adenitis represented 17% of the cases and systemic diseases 4%. Diagnosis was obtained by histological examination of a lymph node biopsy in 80% and by cytology alone in 13% of the patients; no correlation was found between anatomic location, clinical and biological data and any pathological group. Univariate age-independent analysis showed significant correlation between intra-abdominal lymphadenopathy (P=0.05), increased serum CRP (P=0.01) and LDH levels (P=0.05) and malignancy, whereas superficial unique lymph node location (P<0.05), absence of deep site location (P<0.01), and presence of hyperbasophilic cells (P<0.01) were all related to benign non specific adenitis.

CONCLUSIONS

FUO/IUO with lymphadenopathy must be considered as a separate entity, mostly represented by malignancies and granulomatosis, mainly of infectious or malignancy related origin. Fever, intra-abdominal lymphadenopathy, serum CRP and LDH levels and hyperbasophilic cells are relevant indicators.