Inflammatory pseudotumours of the spleen

Inflammatory Pseudotumor of the Spleen: A Case Report and Review of the Literature

The authors report the case of an inflammatory pseudotumor found incidentally in the spleen of a 53-year-old woman who had undergone splenectomy for the treatment of immune thrombocytopenic purpura. An ultrasound performed 2 months prior to the operation showed a spleen of normal size with no appreciable masses; however, gross examination of morselized splenic tissue removed by laparoscopic splenectomy revealed two small, well-circumscribed, white–tan nodules measuring 0.8 and 1.5 cm admixed with otherwise normal-appearing splenic parenchyma. Microscopically, these mass lesions were inflammatory pseudotumors composed of a variable mixture of polyclonal populations of mature lymphocytes and plasma cells with eosinophils, neutrophils, histiocytes, and fibrous tissue. This case represents a rare splenic lesion in our review of the world literature. Inflammatory pseudotumors of the spleen are usually solitary, often asymptomatic, rarely diagnosed prior to surgical removal, and characterized by a varied but uniformly benign histologic appearance. Recognition of this entity by clinicians and pathologists is important in definitively ruling out malignancy of the spleen.

Inflammatory myofibroblastic tumors in childhood: a report from the Italian Cooperative Group studies

BACKGROUND

Inflammatory myofibroblastic tumors (IMTs) are myofibroblastic lesions with unpredictable biologic behavior that occur at a young age. For this report, the authors investigated clinicopathologic features in a series of pediatric IMTs. The objective of the study was to identify morphologic or immunohistochemical prognostic markers and the possible pathogenic role of human herpes virus 8 (HHV-8).

METHODS

Twenty-six patients were observed over a period of 18 years. Clinical/histologic data were reviewed, and immunohistochemical/molecular studies were performed.

RESULTS

Patients ages 8-216 months (median age, 60 months) presented with tumors of the lung-bronchus (8 patients), abdomen (17 patients), and thoracic wall (1 patient). Twenty-one patients underwent complete excision, and microscopic or macroscopic residual disease was present in 5 of those patients. Chemotherapy was received by 5 patients. After a median follow-up of 6.6 years, 24 patients were in complete remission, and 2 patients had died of disease. Local recurrences were observed in 6 patients (including 4 recurrences that occurred after a complete excision). Cytologic atypia, low inflammatory infiltrate, and a rich myxoid pattern were detected in patients who had recurrent disease or a poor prognosis. Anaplastic lymphoma kinase (ALK) was positive in 7 patients (including 2 patients with recurrent disease). No correlation between clusterin expression and prognosis was demonstrated. HHV-8 was identified in 1 pulmonary IMT.

CONCLUSIONS

IMTs are locally aggressive lesions. In this series, the local recurrence rate was 23%, and the 5-year and 10-year event-free survival rates were 87.4% and 72.8%, respectively. The results indicated that the treatment of choice is a complete, nonmutilating excision; chemotherapy may be given to patients who have microscopic or macroscopic residual disease, although the results are controversial; cytologic atypia and positive ALK status are more frequent in aggressive tumors, whereas metastatic tumors are negative for ALK; and HHV8 is not involved in the pathogenesis of IMT.

Inflammatory pseudotumor of the spleen managed laparoscopically. Can preoperative imaging establish the diagnosis? Case report and literature review

BACKGROUND

Inflammatory pseudotumor of the spleen, or inflammatory myofibroblastic tumor, is an uncommon condition easily mistaken for a malignant process. Patients may be asymptomatic or may present with nonspecific abdominal complaints. Mild constitutional symptoms have also been reported. The ability to diagnose this entity radiographically preoperatively may allow the uniform application of laparoscopy to manage this condition and spare patients open splenectomy.

METHODS

Chart review and literature review.

RESULTS

Inflammatory pseudotumor of the spleen was successfully managed laparoscopically. Preoperative evaluation suggested but could not confirm the diagnosis.

CONCLUSIONS

A hypovascular solid splenic mass by Doppler ultrasound or CT scan suggests the diagnosis of inflammatory pseudotumor. Stellate central calcifications seen on CT scan make the diagnosis very likely. Laparoscopic splenectomy can be used for definitive diagnosis and symptomatic relief with minimal morbidity and mortality.

Inflammatory pseudotumor of the liver

Inflammatory pseudotumor of the liver (IPL) is a rare benign neoplasm. It often masquerades as a malignancy, either primary or metastatic. We describe the case of a 71-year-old man who presented with fever and malaise. Workup revealed a cecal mass, as well as a lesion in the left lobe of the liver. Pathologic examination showed a cecal neoplasm and a hepatic inflammatory pseudotumor. The patient recovered uneventfully. This case highlights the ability of IPL to masquerade as a malignant hepatic neoplasm, and emphasizes the difficulties in diagnosis.

Inflammatory pseudotumor of the liver associated with Crohn's disease

Inflammatory pseudotumor (IPT) of the liver is a rare, benign lesion that is characterized by proliferating fibrous tissue infiltrated by inflammatory cells. The exact etiology of IPT remains unclear. Although the association of IPT with systemic inflammatory disorders has been established, a specific link with Crohn's disease is rare. We report two cases of IPT associated with Crohn's disease. Both patients were elderly males who presented with abdominal pain and jaundice. At the time of presentation, both had active Crohn's disease that was undiagnosed. Computed tomography demonstrated a liver mass, and endoscopic retrograde cholangiography revealed biliary strictures in both patients. Given their symptomatic jaundice and concern for cholangiocarcinoma, they underwent abdominal surgical exploration and pathology results revealed IPT. They were subsequently diagnosed with Crohn's disease. Following treatment of Crohn's disease, there was significant improvement in their overall clinical status. An underlying diagnosis of inflammatory bowel disease should be considered in patients with IPT.

Malignant lymphoma of the stomach in association with inflammatory myofibroblastic tumor of the spleen. A case report

We report on a case of a 40-year-old male patient who underwent a gastrectomy because of a biopsy-proven large B-cell lymphoma of the stomach. On surgery, a nodule in the spleen also was noted. Grossly and microscopically, the two lesions were different: the tumor of the stomach appeared white-gray on the cut surface and was a centroblastic variant of diffuse large B-cell lymphoma. Histologically, one perigastric lymph node was involved. Grossly, the splenic nodule was gray-yellow and had a histological appearance of an inflammatory myofibroblastic tumor (IMT). The association between malignant tumor and IMT is rare. In such an association, the latter lesion most often has been reported in the spleen. As EBV may be involved in the genesis of both lymphoma and IMT, we tested both lesions for its presence using in situ hybridization, but the tests were negative. It remains to be verified whether the association between lymphoma and IMT is more than fortuitous.

Inflammatory pseudotumor of the spleen with EBV positivity: report of a case

Inflammatory pseudotumor (IPT) of the spleen is a rare benign tumor with unknown etiology. It causes problems in the diagnosis because of mimicking some hematopoetic malignancies. Here we report the case of a 36-yr-old woman complaining of nausea and insomnia. Laboratory investigations were limited to increase of leukocyte and thrombocyte count. Ultrasonography and magnetic resonance (MR) imaging showed circumscribed solid lobulated mass, measuring about 6.5 cm in diameter, located in the dorsal region of the spleen. Splenectomy was performed with the differential diagnosis including hamartoma and lymphoma of the spleen. Histological examination of the sharply demarcated splenic mass consisted of myofibroblasts and admixture of inflammatory cells. Immunohistochemistry and in situ hybridization were performed. IPT of the spleen was diagnosed. Epstein-Barr virus (EBV) was detected in the tumor by in situ hybridization. This rare entity is presented because of its clinical, radiological and pathological difficulties in the differential diagnosis.

Two splenic lesions in need of clarification: hamartoma and inflammatory pseudotumor

This short review is dedicated to a precise pathologic characterization of 2 uncommon and poorly defined lesions of the spleen and to their distinction from histologically similar processes. Splenic hamartoma represents an abnormally formed red pulp and is characterized by the presence of sinus-like structures lined by CD8(+) endothelia. The great variety of its morphologic appearances may result from the preponderant growth of one or another of the several components of the red pulp, ie, CD34(+) capillaries, myoid cells and macrophages. Therefore, it is proposed that "cord capillary hemangioma," myoid angio-endothelioma, and histiocyte-rich tumors are part of the spectrum of splenic hamartoma. Inflammatory pseudotumor (IPT) of the spleen is a reactive lesion, probably of multiple etiologies, characterized by a mixture of inflammatory cells and a minor, disorganized component of spindle cells. The latter include fibroblasts, SMA(+) myofibroblasts, and CD68(+) spindled histiocytes, establishing a close similarity with the IPT of the lymph node. This benign process needs to be distinguished from 2 others that have a predominant spindle cell component arranged in parallel bundles: the IPT-like follicular dendritic cell tumor, which is consistently associated with Epstein-Barr Virus; and the inflammatory myofibroblastic tumor, also often Epstein-Barr Virus-related and similar to those of the soft tissues, lung and other organs. These 2 lesions are neoplastic and therefore have a potentially worse prognosis than IPT.

Inflammatory pseudotumor of the liver: demographics, diagnosis, and the case for nonoperative management

BACKGROUND

Inflammatory pseudotumor of the liver (IPL) is an unusual tumor-like condition that is becoming recognized as an important differential diagnosis in the patient presenting with liver masses. This report describes six cases of IPL.

STUDY DESIGN

Clinical, diagnostic, pathologic, and followup data were collected prospectively on six patients presenting to a specialist hepatobiliary unit.

RESULTS

Six patients with IPL presented over a 2-year period. Median age was 35 years (range 2 to 79 years) and five patients were men. Three patients were Polynesian (Tongan and Samoan) and one was New Zealand Maori. Five patients presented with nonspecific symptoms (fever, arthralgia, myalgia) and IPL was an incidental finding in one patient. At presentation, four patients had elevated white cell counts, and five patients had abnormal liver function tests with elevations in alkaline phosphotase and gamma-glutamyl transferase the most commonly seen. Carcinogenic embryonic antigen and alpha fetoprotein were normal in all patients, although one was a known hepatitis B carrier. In all cases of IPL, diagnosis was made on core biopsy of the liver lesions and all patients were managed nonoperatively with complete resolution of the tumors. Two patients had marked reduction in systemic symptoms (fever and pain) from a short course of oral steroids.

CONCLUSIONS

IPL appears to be a relatively common problem in Maori and Polynesians. Recognition and differentiation of this condition from malignant liver lesions are important to avoid unnecessary surgery.

Splenic inflammatory myofibroblastic tumor (inflammatory pseudotumor): a clinicopathologic and immunophenotypic study of 12 cases

CONTEXT

Inflammatory pseudotumor is an uncommon and enigmatic lesion. The spindle cells found in this tumor have features of myofibroblasts. Because of the indefinite relationship of these lesions with inflammatory fibrosarcoma and their indefinite biologic behavior, inflammatory pseudotumor is currently classified as inflammatory myofibroblastic tumor (IMT). To date, only case reports or small series have been published on these tumors, which are primary in the spleen.

DESIGN

In this study, we describe the clinical, morphologic, and immunophenotypic findings of 12 cases of splenic IMT and examine their relationship to Epstein-Barr virus (EBV).

RESULTS

The patients included 8 women and 3 men, ranging from 19 to 77 years of age (mean, 53 years; median, 60 years). Demographic data were unavailable for 1 patient. Patients generally presented with abdominal pain (n = 5) and fever (n = 4). Associated lesions included renal cell carcinoma (n = 2), colonic adenocarcinoma (n = 1), and cholecystitis (n = 1). All tumors were composed of a bland spindle cell proliferation in association with a variable mixed inflammatory component. There were 2 growth patterns, namely, a cellular spindle cell pattern and a hypocellular fibrous pattern. An immunohistochemical panel confirmed the myofibroblastic nature of the spindle cells. The spindle cells of 2 cases were immunoreactive for EBV latent membrane protein 1, whereas 6 of 10 cases were positive for EBV-encoded RNA using in situ hybridization. Follow-up was available for 8 patients; 6 were alive with no evidence of recurrence and 2 were dead of other causes.

CONCLUSION

Splenic IMTs are uncommon lesions that can be distinguished from other conditions using a combination of clinical, histologic, and immunophenotypic findings. Epstein-Barr virus may play a role in the pathogenesis of splenic IMT, and there may be an association of splenic IMT with concomitant disease or malignancy. Most splenic IMTs have an excellent long-term prognosis.

Tc-99m colloid and Ga-67 imaging of splenic inflammatory pseudotumor correlation with ultrasound, CT, and MRI

Splenic inflammatory pseudotumor is extremely rare and may mimic splenic neoplasms, such as lymphomas or hamartomas, clinically and radiologically. A case of a surgically proved splenic inflammatory pseudotumor is presented in which Tc-99m colloid SPECT and Ga-67 scintigraphy characterized the changes in the spleen, but the findings of ultrasound and unenhanced CT and MRI were nonspecific. This report indicates the utility of radionuclide imaging for diagnosing splenic inflammatory pseudotumor.

Inflammatory pseudotumor of the spleen in a young child

We describe a case of an inflammatory pseudotumor of the spleen in a 5-year-old boy, found incidentally during a physical examination. The boy underwent a hemisplenectomy. The problems in differentiating this disease from lymphoma of the spleen before surgery and the advantages of hemisplenectomy are discussed. This rare disease has previously been described in the spleen in only 28 cases, the youngest being a 16-year-old patient.

Inflammatory pseudotumour of the spleen

Inflammatory pseudotumours are benign tumour-like masses of unknown aetiology that show microscopically a range of inflammatory and reactive responses and are of importance because they may be mistakenly identified as neoplasms. This case report describes a 15 year old girl with a cystic inflammatory pseudotumour of the spleen in whom a partial splenectomy was performed with a satisfactory outcome.

Frequent presence of the Epstein-Barr virus in inflammatory pseudotumor

Inflammatory pseudotumor is a presumably nonneoplastic, hematopoietic, and spindled fibrous proliferation that may occur at a variety of anatomic sites. The origin of these proliferations is generally unknown. To evaluate the role of the Epstein-Barr virus (EBV) in inflammatory pseudotumor, 18 specimens from 17 patients were studied by in situ hybridization for EBV ribonucleic acid (RNA), and the morphological and immunologic characteristics of the infected cells were evaluated. These specimens included 10 lymph nodes, six splenic masses, and two hepatic masses. Overall, EBV RNA was detected in 41.2% (seven of 18) of the cases. These included two of 10 (20%) lymph nodes, four of six (66.7%) splenic pseudotumors, and one of two (50%) hepatic lesions. The degree of EBV infection was significantly greater within the tumors in comparison with the surrounding, uninvolved tissue. Two morphologically different EBV-positive cell types, spindled and round cells, were evident, and the infected cell type differed significantly when the nodal and extranodal cases were compared. All of the positive extranodal cases shown, numerous EBV-positive spindled cells, whereas no positive spindle cells (only positive round cells, morphologically consistent with lymphocytes) were noted in the two EBV-positive lymph node pseudotumors. Double-labeling immunohistochemical and in situ hybridization studies in some cases identified rare EBV-positive B cells and rare EBV positive T cells in four and three cases, respectively. Most EBV-positive cells in all cases failed to immunoreact with any B- or T-cell markers. Three of five cases studied, however, did show a subpopulation of smooth muscle actin/EBV-positive spindled cells, five of seven cases showed vimentin/EBV-positive spindled cells, and one of four cases had EBV-positive spindled cells that immunoreacted as follicular dendritic cells. These results suggest that EBV plays a role in a significant number of cases of inflammatory pseudotumor with differences in the incidence of EBV infection and the cell type (spindled vs round cell) infected when extranodal and nodal cases are compared, suggesting a difference in pathogenesis. The cell type infected in extranodal cases seemed to be of mesenchymal origin but could not be clearly defined.