Objectives: To describe the case of a patient presenting with weight loss and a pelvic mass. Materials and methods: We performed an advanced search in MEDLINE using the key words "wasting syndrome", "actinomycosis" and "pelvic mass". Results: A 63-year-old woman had a well-delimited and tender pelvic mass and was found to be anaemic. Before scans were performed, clinicians considered malignancy and other diagnoses. Conclusion: Actinomycosis is a chronic infection that usually affects the abdomen. Because of the lack of specificity of clinical and radiological findings, a multidisciplinary approach is the keypoint for making an accurate diagnosis. LEARNING POINTS • Wasting syndromes not related to malignancy are rare but can mimic a typical paraneoplastic wasting syndrome. • Although a pelvic mass is often due to gynaecological involvement, a broad differential diagnosis should first be considered. • In contrast to the principle of Occam's razor, the simplest explanation is not always the correct one.

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