Aanhoudende koorts zonder focus met lymfadenopathieën: infectie, inflammatie of maligniteit?

Persistent fever without focus but with lymphadenopathy: infection, inflammation or malignancy? Adult-onset Still’s disease (AOSD) is a rare auto-inflammatory disease in which four cardinal signs have been described: rash, spiking fever, arthritis or arthralgia and hyperleucocytosis with neutrophilia. Nevertheless, diagnosis can be challenging as infectious, other inflammatory or neoplastic diseases need to be ruled out. It affects typically young adults (from 16 to 35 years). The disease can be controlled with non-steroidal anti-inflammatory agents and glucocorticoids. To date, treatments as Il-6, IL-1 or anti-TNFα can be used in glucocorticoid-dependent or refractory patients. We present a case of a 22-year old woman with all four cardinal symptoms in which all cultures and infectious serology resulted negative. Also, auto-immune markers were negative. Because of diffuse bilateral supra- and infradiaphragmatic enlarged lymph nodes up to 1.6 cm in size on computed tomography (CT), additional positron emission tomography-computed tomography imaging (PET-CT-scan) was performed. Besides the multiple enlarged lymph nodes, increased tracer capture was shown in the spleen and bone marrow. All of this was suspicious for high-grade lymphoma. Eventually, an additional bone marrow biopsy with aspiration and lymph node biopsy could rule out a lymphoproliferative process and the diagnosis of AOSD could be made. This case report highlights the importance of a profound diagnostic work-up in fever of unknown origin.