Inflammatory pseudotumor-like follicular dendritic cell tumo
Often dubbed the “forgotten organ,” the spleen and many of its normal physiological roles are still poorly understood and often overlooked. Though incidentally encountered splenic lesions can be a challenge, the majority of these lesions are benign. A wide spectrum of splenic lesions exists ranging from post-traumatic findings to vascular neoplasms such as hamartomas, lymphangiomas, and SANTS (sclerosing angiomatoid nodular transformation). Imaging features suggestive of malignancy have been identified including absence of splenomegaly, ill-defined margins, solid nature, lack of calcification, and the presence of underlying malignancy.

One extremely rare neoplasm of the spleen is the follicular dendritic cell tumor. Often present in cervical and axillary nodes, follicular dendritic tumors can occur in extra-nodal sites such as the tonsils, lungs, gastrointestinal tract, orbits, and, as we report here, within the spleen. A 44-year-old woman, without significant underlying history, presented with nonspecific abdominal pain for a few months. Both a contrast-enhanced computed tomography and magnetic resonance imaging revealed a new 2.5 cm enhancing splenic lesion, which demonstrated hypermetabolic activity on subsequent positron emission tomography and computed tomography scans. Since the lesion was new compared to more remote imaging and hypermetabolic, a splenectomy was performed. Pathology confirmed the diagnosis and demonstrated positivity for Epstein-Barr Virus .