Inflammatory Pseudotumor of the Spleen in a Patient with Idiopathic Thrombocytopenic Purpura

Abstract

Inflammatory pseudotumor tumors (IPTs) of the spleen are uncommon lesions of uncertain pathogenesis. A definitive clinical diagnosis is challenging because radiological, as well as gross pathologic features may suggest a lymphoma, an inflammatory myofibroblastic tumor (IMT), or an IPT-like follicular dendritic cell tumor (IPT-FDC). Herein, we report a case of an IPT of the spleen in a 48-year-old woman who presented with idiopathic thrombocytopenic purpura (ITP) symptoms. The results of abdominal ultrasonography revealed the presence of a splenic mass that continued to enlarge after the recovery from ITP, leading to the suspicion of lymphoma. A splenectomy was performed for diagnostic and curative purposes. The lesion was a non-encapsulated yellowish mass (largest diameter: 4,4 cm). The presence of spindle cells expressing smooth muscle actin, vimentin, and focal CD68 admixed with polymorphous lymphoid infiltrate supported the IPT diagnosis. The negative expression of CD21, CD23, CD35, and ALK excluded inflammatory myofibroblastic and follicular dendritic cell tumors. Any evidence of the recurrence of either ITP or IPTs was not noted 60 months after the operation. The present case and the review revealed that splenic IPT tends to occur in middle-aged females and diagnosis is challenging due to the absence of specific symptoms or the characteristic hematological or radiological findings. Surgery is the most frequently performed treatment. Although multiple factors have been suggested in the etiology and pathogenesis, previous bleeding may also play a role in the presence of IPTs in patients with ITP. The rare occurrence of splenic IPT and the lack of diagnostic clinical signs and symptoms do not exclude their consideration in the differential diagnosis of spleen tumors, especially in patients with imaging features that cannot rule out malignancy.