Inflammatory Pseudotumor (IPT) forms a group of etiologically, histologically, and biologically heterogeneous tumefactive lesions that are histologically characterized by prominent inflammatory infiltrates. It has been described in various organs including the lungs, bladder, liver, spleen, heart, and others. It may mimic a malignant tumor clinically and radiologically. Splenic IPT are most frequently detected incidentally. We report a case of 38-year-old women admitted for recurrent abdominal pain. Physical examination was unremarkable. Contrast enhanced CT showed a well hypodense, circumscribed lesion, measuring 5 × 3.5 cm. A differential diagnosis of lymphoma, teratomas, angioma or angiosarcoma was considered. The patient underwent splenectomy. Histologically, the tumor consisted of an inflammatory infiltrate composed predominantly of diffusely lymphoplasmocytic cells and stromal fibroblasts. Epstein-Barr virus was detected on in situ hybridization exclusively in the epitheloid and spindles cells. The optimal management of this tumor and eventually in asymptomatic patients is still controversial. IPT of the spleen should be remembered when evaluating single or multiple nodules in spleens. The clinical and pathological features of previously reported cases are reviewed in this paper.
The term Inflammatory Pseudotumor (IPT) has historically been applied to heterogeneous group of mass-form- ing lesions characterized by a prominent inflammatory infiltrate as the predominant cellular component. They have been observed in various parts of the body including the orbit, respiratory tract, gastrointestinal tract, and soft tissues, lymph nodes and liver. IPT of the spleen is extremely rare and is frequently misdiagnosed as malignant neoplasms or other benign tumors.
In this report, we report an IPT of the spleen, and pay particular attention via a review of the literature to the diagnosis modalities, differentiated diagnosis and treatment of such tumors.
A 38-year-old woman admitted to our department for a six-month history of upper left side pain of an intermediate severity. There was no history of constitutional symptom, overseas travel, and trauma or alcohol abuse. She did not have any other clinical symptom such as fever, appetites loss or weight loss. Physical examination showed no hepatomegaly, splenomegaly or lymphadenopathy. Laboratory findings were unremarkable except for slightly elevated white blood cell count (11,300/mm3) and C-reactive protein level (135 mg/ml). Abdominal Ultrasonography showed a hypoechoic splenic mass and enhanced abdominal computed tomography revealed the presence of a low density, hypovascular, centrally, well defined mass measuring 5 × 3.5 cm (
Under diagnosis of a malignant tumor like lymphoma or atypical angiosarcoma, laparotomic splenectomy was performed. Grossly, the specimen of the spleen measured 11 × 7.5 cm in size and weighed 210 gr (
The postoperative course was uneventful and the patient fit well six months after surgery with no sign of recurrence or lymphoproliferative disorder.
IPT are relatively rare lesions characterized by chronic infiltration of inflammatory cells and areas of fibrosis. They have been observed in various parts of the body including the orbit, respiratory tract, gastrointestinal tract, and soft tissues, lymph nodes and liver [
The clinical signs and symptoms are most divers, with pain in the left flank or hypochondrium like in our case. Pain can be associated in some cases with fever or splenomegaly, while in other cases, patients were
(a) (b)
Grossly aspect of the spleen. The specimen measured 11 × 7.5 cm and weighed 210 gr
Macroscopic view of the specimen: a well circum- scribed, solid and medullary mass, measured 5 × 3 × 3 cm. the major part of the lesion showed yellowish appearance (arrow) with some stippling red spots
Histological findings for the spleen via hematoxylin and Eosin staining showing infiltration by lymphocytes and plasma cells (original magnification ×200 and 400)
in situ hybridization for Epstein-Barr Virus-encoded nuclear RNA1 and RNA2 shows strong staining in the epithe- loid and spindles cells (×200)
asymptomatics [
Biological findings are also no specifics and often normal. In some cases, laboratory studies showed anemia and leucocytosis due to the chronic inflammation [
Recent advances in imaging are helpful in the identification of space occupying lesions of the spleen but, no radiological findings have been found that are characteristics of IPT. This may be because the proportion in the distribution of inflammatory cells and fibrosis differs according to the cause and the period of inflammation [
Although CT and MRI are quite sensitive, they are not specific in differentiating between splenic IPT and other malignancies. There are some reports emphasizing the importance of undertaking percutaneous fine-needle biopsy in cases of hepatic or splenic IPT to avoid unnecessary surgery [
Splenic IPT frequently mimic the splenic neoplasms clinically and radiologically. Radiological findings as described above are not sufficiently specific to differentiate this type of lesion from other neoplasm including lymphoma, teratoma, angioma, angiosarcoma, or abscess [
Gross features in reported cases of splenic IPT are described as a solitary well-circumscribed lesion with white or yellow cut surface that compresses the adjacent splenic parenchyma which is consistent with the findings in our case [
The etiology and pathogenesis of this entity are unknown. Infections, vascular causes and autoimmune disorders have been hypothesized in their pathogenesis. Infection is one hypothesis [
The prognosis of IPT has generally been considered favorable after splenectomy according to the previous published cases [
In conclusion, we report a rare case of splenic IPT confirmed by histological examination of the spleen. It is currently a relatively rare pathology not associated with specific clinical findings. No imaging techniques allow preoperative diagnosis. The place and indication of percutaneous biopsy are debated. Most often, only splenectomy and histopathological study of the specimen allow diagnosis and treatment of this entity. A subset of these tumors harbors the EBV in epitheloid and spindle cells, and they must be distinguished from other IPT like tumors such IPT like FDC tumor and inflammatory myofibroblastic tumor because these two lesions are neoplastic and can show a worse prognosis.
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