A malignancy must be carefully excluded before ruling in the diagnosis of adult onset Still's disease (AOSD). However, an occult or poorly symptomatic malignancy can easily be overlooked.
We report a 50-year-old female patient who presented with features of adult onset Still's disease (AOSD), in fact heralding a malignant melanoma with fatal outcome since discovered lately, at a metastatic stage. In retrospect, the only significant atypical feature was cholestatic hepatitis, which soon disappeared upon institution of glucocorticoid treatment. The literature review identified 27 additional cases of AOSD-like disease associated with malignancy published since 1980 including solid cancer in 61% of the cases (especially breast and lung) and haematological malignancies in 39% of the cases (especially malignant lymphoma). The interval between OASD-like symptoms and malignancy averaged 8 months, and AOSD most often preceding malignancy. Although idiopathic AOSD and neoplastic AOSD-like disease are often indistinguishable initially, some features could point toward the latter: an onset of AOSD after the age of 40 years, the presence of atypical clinical, biological, or immunological features in less than one third of the cases, and a poor response to NAIDS or systemic glucocorticoids in 61% of the cases.
Making the differential diagnosis of malignancy-associated AOSD in a timely fashion remains a primary goal, even in the most typical cases and those showing good initial therapeutic response.