Uterine intravascular lymphoma as a cause of fever of unknown origin.

Primary intravascular large B cell lymphoma (IVL) remains a diagnostic challenge because of non-specific clinical, laboratory and imaging findings. The aim of the study was to analyse the major characteristics of IVL with uterine involvement. We retrospectively collected features of IVL with uterine involvement that was proven histologically or demonstrated by significant 18FDG uptake on 18FDG-PET/CT. Findings were compared to a comprehensive literature review. Five patients were identified. All of them were admitted for fever of unknown origin (FUO), with haemophagocytic lymphohistiocytosis in three cases. None had gynaecological symptom, contrasting with the literature data. Structural imaging (including whole-body CT scan and pelvic RMI) failed to yield any diagnosis. 18FDG-PET/CT showed intense uterine uptake in all cases. Endometrial biopsy was performed in three cases and was positive in one. Diagnosis was obtained from coelioscopic iliac adenopathy biopsy in one case and from total hysterectomy in another. Punch biopsy of skin lesions led to diagnosis in the two remaining cases. Bone marrow biopsy was normal in all cases. Clinicians should be aware of potential isolated uterine involvement in IVL, especially in elderly women with FUO. Normal structural imaging does not rule out the diagnosis and 18FDG-TEP/CT should be performed to guide high-yielding biopsy.