Inflammatory pseudotumor of the liver. Clinicopathologic study and review of the literature

Inflammatory Pseudotumor of the Liver or Intrahepatic Cholangiocarcinoma, That's the Question: A Review of the Literature

An inflammatory pseudotumor of the liver is a rare tumor-like lesion composed of polymorphous inflammatory cell infiltrates and variable amounts of fibrosis that can often mimic a malignant liver neoplasm. The etiology of inflammatory pseudotumors of the liver is unknown; symptoms are faint and imaging non-specific. Thus, it is often hard to make a diagnosis preoperatively and it is not so rare to over-treat patients with this disease or vice versa. Thus, more profound knowledge is necessary to plan appropriate disease management. We reported our two cases and systematically searched the literature regarding IPTL. We selected articles published in English from four databases, PubMed, Scopus, Web of Science and Google Scholar, and we included only articles with consistent data. Twenty nine papers fulfilling criteria for the review were selected. The analysis of 69 cases published from 1953 confirmed that the risk factors are unclear, the imaging data is not specific, and biopsy is crucial but not so widely used in clinical practice due to the procedure's related risks, and relatively low effectiveness and improvement in imaging analysis. Regarding treatment, surgeons have moved towards a more conservative attitude over the years due to better imaging quality and patient surveillance. However, surgery remains the modality of choice for most cases with an indeterminate diagnosis. Even if an inflammatory pseudotumor of the liver is a benign tumor with a good prognosis, not requiring any treatment in most cases, sometimes it remains challenging to differentiate it from ICC; therefore, there is a solid recommendation to manage this condition with a multidisciplinary team.

Case report: An inflammatory pseudotumor of the caudate lobe of the liver caused by a foreign body

This case report explores a rare foreign body-induced inflammatory pseudotumor in the caudate lobe of a 47-year-old male. The patient was admitted to the hospital due to epigastric pain and fever. Radiological examinations led to the diagnosis of a malignant tumor, and a resection of the caudate lobe lesion was performed. The excised tumor specimen revealed a fishbone-like foreign body. Immunohistochemistry suggested that this was an inflammatory pseudotumor rather than a malignant tumor. This prompted us to contemplate the origin of the foreign body and the mechanisms by which it led to the formation of the inflammatory pseudotumor.

Hepatic Inflammatory Pseudotumor-Focusing on Its Heterogeneity

Hepatic inflammatory pseudotumors (IPTs) are defined as benign, non-malignant, non-metastasizing tumors characterized by the presence of myofibroblastic spindle cells, hetorogenous populations of inflammatory cells, particularly plasma cells, lymphocytes and macrophages, as well as locations of fibrosis and necrosis without cellular anaplasia or atypical mitoses. Despite subsequent reports in the references, hepatic IPT remains difficult to diagnose; while posing major issues specifically for its differential diagnosis compared with that of other various benign diseases and malignant hepatic tumors. Histopathological findings are always a requisite for confirming the diagnosis, particularly given that the pathogenesis of IPT remains ambiguous to date. Hepatic IPT is a heterogeneous entity in terms of its clinical features, pathological findings, and pathogenesis. Once the diagnosis is confirmed, however, needless surgery such as wedge resection and lobectomy should be avoided. Here, we discuss the heterogeneity of hepatic IPT, its clinical features, pathological findings, and pathogenesis, and describe its differential diagnosis.

Inflammatory Pseudotumor of the Liver

Hepatic inflammatory pseudotumor (IPT) describes a mass lesion composed of fibroblasts or myofibroblasts with a dense inflammatory infiltrate comprising lymphocyte, plasma cells, and histiocytes. These lesions are presumed to be an exuberant response to an infectious organism, although in most cases the causative agent is unknown. In specific circumstances, pathologists should consider ancillary techniques to exclude specific infections, such as mycobacteria, Candida, or syphilis. IgG4-related disease may cause a plasma-cell rich IPT. Finally, true neoplasms can mimic IPTs and must be excluded with appropriate ancillary studies, including inflammatory myofibroblastic tumor, follicular dendritic cell tumor, inflammatory angiomyolipoma, Hodgkin lymphoma, and inflammatory hepatocellular carcinoma.

Magnetic resonance imaging of inflammatory pseudotumor of the liver: a 2021 systematic literature update and series presentation

PURPOSE

Inflammatory pseudotumors of the liver (IPTL) are not exceptional benign lesions with various etiologies, histology, and imaging appearances. The incomplete knowledge of this pathology and the wide polymorphism sometimes resembling malignancy often induce long and expensive diagnostic flow, biopsy and occasionally unnecessary surgery. We propose a systematic revision of MRI literature data (2000-2021) with some narrative inserts and 10 new complete MRI cases, with the aim of organizing the data about IPTL and identifying some typical features able to improve its diagnosis from imaging.

METHODS

We performed a systematic revision of literature from 2000 to 2021 to obtain MRI features, epidemiological, and clinical data of IPTL. The basic online search algorithm on the PubMed database was "(pseudotumor) AND (liver) AND (imaging)." Quality assessment was performed using both scales by Moola for case report studies and by Munn for cross-sectional studies reporting prevalence data. A case-based retrospective study by collecting patients diagnosed with IPTL from three different university hospitals from 2015 to 2021 was done as well. Only cases with MR examinations complete with T1/T2/contrast-enhanced T1/Diffusion-Weighted (W) images and pathology-proven IPTL were selected.

RESULTS

After screening/selection 38 articles were included for a total of 114 patients. In our experience we selected 10 cases for a total of 16 IPTLs; 8 out of 10 patients underwent at least 1 MRI follow-up. Some reproducible and rather typical imaging findings for IPTL were found. The targetoid aspect of IPTL is very frequent in our experience (75% on T1W, 44% on T2W, 81% on contrast-enhanced T1W (at least one phase), 100% on Diffusion-W images) but is also recurrent in the literature (6% on T1W, 31% on T2W, 51% on CE-T1W (at least one phase), 18% on Diffusion-W images, and 67% on hepatobiliary phase). In our experience, Apparent Diffusion Coefficient map values were always equal to or higher than those of the surrounding parenchyma, and at MRI follow-up, nodule/s disappeared at first/second control, in six patients, while in the remaining 2, lesions persisted with tendency to dehydration.

CONCLUSION

A targetoid-like aspect of a focal liver lesion must raise diagnostic suspicion, especially if IgG4-positive plasma is detected. MRI follow-up mainly shows the disappearance of the lesion or its reduction with dehydration.

Fibrohistiocytic Variant of Hepatic Pseudotumor: An Antibiotic Responsive Tumefactive Lesion

Inflammatory pseudotumor is a term used to designate inflammation-rich tumefactive lesions. Following the exclusion of specific entities such as IgG4-related disease and other neoplastic entities previously included in this entity, the majority of hepatic pseudotumors show a prominent fibrohistiocytic inflammatory reaction and have been previously categorized as fibrohistiocytic variant of hepatic pseudotumor (FHVHPT). The goal of this study was to examine the clinical, radiologic, histologic, and etiologic aspects of this entity. After excluding neoplastic diseases, we identified 30 patients with FHVHPT from 3 institutions between 2009 and 2019. We extracted demographic and clinical data, liver function tests as well as culture results and radiologic information. Hematoxylin and eosin-stained slides were reviewed for pattern of inflammation as well as its cellular composition. Immunohistochemistry for IgG4 and IgG was performed in all cases. The mean age of the 30 lesions characterized as FHVHPT was 56 years (range: 23 to 79 y). Nineteen patients showed solitary lesions; 11 were multiple. The mean size of the lesion was 3.8 cm (range: 1 to 7.5 cm). On imaging, a neoplastic process or metastasis was the leading diagnostic consideration (n=15, 50%). The most common symptom was abdominal pain (n=14/30); 8 patients presented with symptoms compatible with an infectious process, including fever. The inflammatory infiltrate was dominated by lymphocytes and plasma cells, and in most cases, a prominent histiocytic infiltrate (22/30). Neutrophils were identified in 12 cases, with microabscess noted in 8. Storiform pattern of fibrosis was seen in 14/30 cases; obliterative phlebitis was not identified. Culture identified a microorganism in 4 of 9 cases evaluated. The mean IgG4 count was 9.3 per HPF (range: 0 to 51) with 9 of the 26 (35%) biopsies showing >10 IgG4 positive plasma cells per HPF. The mean IgG4 to IgG ratio was 8% (range: 8% to 46%). A hepatectomy was performed in 4 cases. On broad spectrum antibiotics (n=14) the lesions either resolved or decreased in size. Eight patients did not receive specific therapy, nevertheless, the lesion(s) resolved spontaneously in 6 cases, remained stable or decreased in size in 2 cases. Notably, none of these patients showed evidence of a hepatic recurrence. FHVHPT, a tumefactive lesion that mimics hepatic neoplasia, is histologically characterized by a fibrohistiocytic infiltrate. In the majority of patients FHVHPT represents the organizing phase of hepatic abscess and can be successfully managed with antibiotic therapy.

Clinicopathological features and post-resection outcomes of inflammatory pseudotumor of the liver

Backgrounds/Aims

Hepatic inflammatory pseudotumor (HIPT) is a rare disease characterized by chronic infiltration of inflammatory cells and area of fibrosis. The objective of this retrospective observational study was to investigate clinicopathological features and outcomes of patients who underwent hepatic resection (HR) for HIPT.

Methods

From 2009 to 2018, seven patients with HIPT underwent HR, accounting for 0.06% of 11,979 adults who underwent HR at our center.

Results

These seven patients included five men and two women. Their mean age was 62.3±11.6 years. In four patients with hepatitis B virus (HBV)-associated liver cirrhosis or chronic hepatitis, liver masses were suspected of hepatocellular carcinoma (HCC) or combined HCC-cholangiocarcinoma based on imaging studies. In three patients without HBV infection, two patients were suspected of HCC, for whom liver biopsy was not performed. One patient was suspected of liver abscess or HIPT, for whom percutaneous liver biopsy was performed and the mass was diagnosed with HIPT. However, this patient underwent HR owing to abdominal pain. No patient presented with abnormally elevated levels of alpha-fetoprotein, protein induced by vitamin K absence or antagonist-II, or CA19-9. During a mean follow-up period of 76.4±34.8 months, no patient experienced recurrence of HIPT.

Conclusions

HIPT, a rare form of liver disease, is often misdiagnosed as malignant liver tumor. Active histological diagnosis is warranted for patients with suspected HIPT to avoid unnecessary operation. HR can be indicated in case of diagnostic ambiguity of HIPT or under a clinical diagnosis of malignant liver tumor.

An Enigmatic Liver Mass in a Child

Hepatic space occupying lesions in childhood are a diagnostic challenge, as they are caused by a variety of malignant and nonmalignant disorders with a different prognosis and, of course, treatment. They are often misdiagnosed or diagnosed only after surgical resection. A 14-year-old boy presented with abdominal pain, evening-rise fever with loss of appetite and weight. The patient also developed jaundice after 2 months of above symptoms. Ultrasound of the abdomen showed an irregular infiltrative mass in segment IV of the liver. Gadobenate disodium magnetic resonance imaging done showed T1 hypointense and T2 hyperintense lesions in segment VIII of the liver with extension into porta with delayed enhancement suggestive of fibrous tumor. Liver biopsy showed extensive liver parenchymal fibrosis with a mixed inflammatory infiltrate with eosinophils. Bacterial, tubercular, and fungal culture of liver biopsy were negative. Although serum IgG4 levels were 7.88 g/L (N =1.9 g/L), IgG4 staining of liver biopsy was negative. The patient was started on prednisolone 1 mg/kg considering the diagnosis of inflammatory pseudotumor (IPT). Twenty days after starting the steroid, mass lesions were converted into multicystic abscess requiring antibiotics and pigtail drainage. On follow-up, patient had improved symptoms with mass lesions turned into small-sized abscess cavity. Hepatic IPTs are difficult to differentiate from malignant tumors, as they are rare and can have variable imaging findings. To avoid inadvertent surgery, histological confirmation of the hepatic mass is essential. Steroids should be used with caution with close follow-up to prevent iatrogenic complications, such as a chronic liver abscess.

Hepatic Inflammatory Pseudotumor Protruding from the Liver Surface and Directly Penetrating the Colon

A 69-year-old man was diagnosed with a liver abscess and received antibiotics at a local hospital. He was referred to our hospital due to a persistent fever. He had hepatic masses protruding from the liver surface toward the transverse colon. We reached a diagnosis of inflammatory pseudotumor (IPT) by a percutaneous liver biopsy. Colonoscopy showed direct invasion of IPT to the colon. His condition improved by the intravenous administration of antibiotics. Hepatic IPT is often misdiagnosed as a malignant tumor. We should consider IPT when we encounter hepatic tumors, and a percutaneous liver biopsy is useful for avoiding unnecessary excessive treatments.

Overlooked and Challenging Encounters–Inflammatory Pseudotumors in the Abdomen and Pelvis: A Pictorial Essay

Inflammatory pseudotumors (IPTs) are uncommon, mass-forming lesions, predominantly involving the lung and orbit. Although the incidence of IPTs is rare in the abdomen and pelvis, they can be encountered as enhancing, soft-tissue lesions, mimicking malignancy or fibrosclerosing disease. Generally, they exhibit a wide range of nonspecific imaging features in various organs. Preoperative imaging diagnosis of IPTs in appropriate clinical settings may help determine proper patient management. In this article, we review radiologic findings of IPTs in the abdominopelvic cavity, including the liver, spleen, kidney, gastrointestinal tract, mesentery, pelvis, and retroperitoneum.

Anaplastic lymphoma kinase-negative pulmonary inflammatory myofibroblastic tumor with multiple metastases and its treatment by Apatinib: A case report

RATIONALE

Primary pulmonary inflammatory myofibroblastic tumor (IMT) with distant metastasis is extremely rare. Moreover, metastasis of pulmonary IMT to bone marrow has never been reported in previous studies. Therapeutic approaches for anaplastic lymphoma kinase (ALK)-negative pulmonary IMT with metastasis are limited. Yet there is no report on the treatment of advanced IMT cases with anti-angiogenesis drugs.

PATIENT CONCERNS

We described a patient with a complaint of fatigue, with the chest computed tomography (CT) scan revealing 2 masses in bilateral lung.

DIAGNOSES

The CT-guided lung biopsy examined 1 lesion in the right lung, and the post-operative pathological diagnosis of ALK-negative pulmonary IMT was recommended. However, the lung lesions were found significantly enlarged during the subsequent visit 8 months later, along with multiple metastases to the bone and abdominal cavity. A bone marrow biopsy revealed bone marrow infiltration by spindle cells.

INTERVENTIONS

The patient began to take Celecoxib due to the rapid progression of IMT, however, resulting in the aggravated gastric ulcer. He stopped taking the medicine 1 month later, with no remarkable change in the lesions by CT. Apatinib was administrated instead of Celecoxib.

OUTCOMES

After the 5-month treatment of Apatinib, the mass in the abdominal cavity significantly shrank and the lung lesions slightly decreased in size. With the 9-month administration of Apatinib, the lung lesions and the abdominal mass kept stable, compared with the situation in the 5-month follow-up.

LESSONS

Although pulmonary IMT shows the potential of metastasis, its metastasizing to bone marrow is a highly unusual event. Apatinib is effective for pulmonary IMT, and should be taken into consideration for the treatment of inoperable pulmonary IMT patients who lack ALK rearrangement.

Spectrum of Pitfalls, Pseudolesions, and Misdiagnoses in Noncirrhotic Liver

OBJECTIVE

The purpose of this article is to illustrate the various pitfalls, mimics, and atypical features that can lead to inaccurate diagnosis of focal lesions in a noncirrhotic liver. The content includes relevant pathogenesis and background as well as specific clues that can be used to reach an accurate diagnosis.

CONCLUSION

When assessing focal hepatic lesions, it is important to avoid pitfalls and misdiagnoses that can alter the management plan. Helpful strategies for avoiding pitfalls include paying close attention to the clinical history of the patient, carefully evaluating all of the available imaging studies, and being aware of the various radiologic mimics.

Inflammatory pseudotumor of the Liver. A Report of Two Cases with Unusual Histologic Picture

Two cases of inflammatory pseudotumor (IPT) of the liver are reported. Clinical presentation was vague and aspecific. Laboratory tests and data from imaging techniques provided no specific information on the actual nature of the lesions and were misleading, suggesting a malignant lesion in one patient and a complicated hydatid cyst in the other. On gross examination, the tumors appeared yellowish ore grey-yellow in color, with a firm cut surface and well circumscribed from the surrounding parenchyma, although a true capsule was not evident. Variability in the histological pattern was also observed, even though the major finding was in both cases an admixture of lymphocytes, plasmacells, granulocytes and monocytes. Lymphocytes were immunohistochemically heterogeneous; monocytes showed in one case large hyperchromic atypical nuclei, confirming the previously, reported possibility that some cases of IPT may be mistaken for sarcomas. Further evidence is added in support of the hypothesis that some liver IPT may result from the evolution of cholangitic abscesses.

Inflammatory Pseudotumor of the Liver: Report of Two Cases

Inflammatory pseudotumor of the liver is a very rare lesion. Herein we describe two cases of this entity which occurred in two women aged 22 and 49 years, respectively. Both cases were considered to be clinically malignant and only the histopathologic examination revealed the non-neoplastic nature of the disease. Ultrastructural and immunohistochemical studies further supported the evidence of a reactive disease.

Imaging features of rare mesenychmal liver tumours: beyond haemangiomas

Tumours arising from mesenchymal tissue components such as vascular, fibrous and adipose tissue can manifest in the liver. Although histopathology is often necessary for definitive diagnosis, many of these lesions exhibit characteristic imaging features. The radiologist plays an important role in suggesting the diagnosis, which can direct appropriate immunohistochemical staining at histology. The aim of this review is to present clinical and imaging findings of a spectrum of mesenchymal liver tumours such as haemangioma, epithelioid haemangioendothelioma, lipoma, PEComa, angiosarcoma, inflammatory myofibroblastic tumour, solitary fibrous tumour, leiomyoma, leiomyosarcoma, Kaposi sarcoma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, rhabdomyosarcoma and hepatic metastases. Knowledge of the characteristic features of these tumours will aid in guiding the radiologic diagnosis and appropriate patient management.

Does pyogenic liver abscess increase the risk of delayed-onset primary liver cancer?: Evidence from a nationwide cohort study

Delayed-onset primary liver cancer (PLC) including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) in patients with pyogenic liver abscess (PLA) is not common. The relationship between PLA and delayed-onset PLC is unclear. We investigated the association in a nationwide cohort study.From Taiwan National Health Insurance claims data, a cohort of 17,531 patients with PLA was generated after excluding patients with a history of cancer (n = 2034) and those diagnosed with PLC (n = 572) and other cancers (n = 627) within 1 year of a diagnosis of PLA. An age-, sex-, index year-, and diabetes mellitus (DM)-matched control cohort of 70,124 persons without PLA was selected from the same dataset. Both cohorts were followed up until the end of 2011. The risk of PLC was estimated for both cohorts.The incidence of PLC was nearly 2-fold greater in the PLA group than in the control cohort (29.3 per 10,000 person-years vs. 16.2 per 10,000 person-years). The incidences of HCC and ICC were 1.5- (22.1 per 10,000 person-years vs. 15.0 per 10,000 person-years) and 11-fold greater (6.73 per 10,000 person-years vs. 0.62 per 10,000 person-years), respectively, in the PLA group than in the control cohort. The PLA cohort also had high risks of PLC (adjusted hazard ratio [aHR] = 1.56; 95% confidence interval [CI] = 1.35-1.81), HCC (aHR = 1.34; 95% CI = 1.15-1.57), and ICC (aHR = 6.94; 95% CI = 4.23-11.57).In conclusion, in this nationwide cohort study, PLA increased the risk of delayed-onset PLC.

A Diagnosis of Inflammatory Pseudotumor of the Liver by Contrast Enhaced Ultrasound and Fine-Needle Biopsy: A Case Report

Inflammatory pseudotumor (IPT) of the liver is a rare, benign lesion of unclear etiology, which may be misdiagnosed as hepatocellular carcinoma, cholangiocarcinoma, secondary tumor or abscess, because of its non-specific clinical, biochemical and radiologic findings. We present the case of a 48-old-year male in whom diagnosis of liver IPT was suspected by contrast enhanced ultrasound (CEUS) and confirmed by fine-needle liver biopsy. The diagnosis is in contrast to most of the literature reports in which the diagnosis was made only based on a surgical specimen.

Immunoglobulin G4-related hepatic inflammatory pseudotumor invading the abdominal wall

A 50-year-old woman presented with epigastralgia. Computed tomography (CT) of the abdomen revealed a 6-cm well-enhanced mass extending from the left lobe of the liver to the abdominal wall, suggestive of cholangiocarcinoma. Liver and skin mass biopsies did not provide evidence of hepatic malignancy but were rich in plasma cells and sclerotic lesions. Subsequent detection of elevated serum immunoglobulin G4 (IgG4) led to a diagnosis IgG4-related inflammatory pseudotumor (IPT) of the liver. Treatment with systemic corticosteroids resulted in rapid clinical improvement. This case is the first report of an IgG4-related hepatic IPT invading the abdominal wall.

Inflammatory Pseudotumor of the Mediastinum Associated With Azacytidine Therapy, Acute Myeloid Leukemia, and Previous Chemotherapy for Astrocytoma

We report the rare case of a rapidly growing inflammatory pseudotumor arising in the mediastinum of a 30-year-old man with myelodysplastic syndrome secondary to treatment for grade 3 astrocytoma. The tumor was discovered soon after discontinuation of 5-azacytidine therapy for myelodysplasia. Fine-needle aspiration was suggestive, and thoracoscopic biopsy was diagnostic. The tumor was excised because of rapid growth and encroachment on the left pulmonary artery and lung. Postoperatively, blastemia was discovered. Acute myeloid leukemia was confirmed by bone marrow biopsy. The patient died of aspiration pneumonia before commencement of leukemia chemotherapy. This case illustrates a rare occurrence of inflammatory pseudotumor in the mediastinum complicating or arising in the setting of multiple primary cancers and chemotherapy. A temporal association with azacytidine therapy is noted. Int J Surg Pathol 3(1):49-58, 1995

Pseudolymphoma (Reactive Lymphoid Hyperplasia) of the Liver Containing Epithelioid Cell Granulomas and Schaumann's Bodies in Giant Cells

Nodular lymphoid hyperplasia, also known as pseudolymphoma (PL), of the liver is a benign reactive process of lymphoid tissue and is extremely rare. To our knowledge, only four cases of hepatic PL have been reported to date. We present a 59-year-old woman patient with hepatic PL that was preoperatively diagnosed as hepatocellular carcinoma (HCC), based on the findings of a variety of imaging modalities. However, resection of the tumor specimen at hepatic lobectomy revealed that the tumor was not a true tumor but a PL composed of proliferated nonneoplastic, polyclonal lymphocytes and plasma cells with abundant lymphoid follicles, together with mononuclear and multinuclear histiocytes with granuloma formation. Sporadic multinucleated giant cells had concentrically or eccentrically laminate ‘conchoidal’ bodies, known as Schaumann's bodies. Immunohistochemical staining of lymphocytes and plasma cells for T and B cells, or IgGK and IgGk revealed the polyclonal nature of these cells. Furthermore, clonal immunoglobulin heavy-chain gene rearrangement was not detected in the lymphoid cells in the lesion with polymerase chain reaction (PCR) analysis. The background hepatic tissue showed no cirrhosis, but some lymphocytes had infiltrated into the portal tracts around the tumor. Since hepatic PL is extremely rare and no association of PL with granuloma with Schaumann's bodies has been described in previously reported cases with hepatic PL, the clinical and histologic features in this case are described with a literature review.

Inflammatory myofibroblastic tumor: A rare cause of invagination in adults

Inflammatory myofibroblastic tumor (IMT) is a distinct pseudosarcomatous lesion arising in the soft tissues and interior organs of children and young adults. It is rarely seen in adults. It was first described in lungs. IMT can occur in any location in the body. However, it is seen most commonly in lungs, intestinal mesentery and liver. Non-mesenteric alimentary tract IMT's are quite rare. The presented case is an ileal IMT that caused small bowel invagination. A 38 year-old male patient presented to the emergency department with the complaint of diffuse abdominal pain, distension and no passage of gas or stools for two days. An abdominal examination revealed distension and tenderness in the abdomen with no guarding or rebound tenderness. Computerized tomography (CT) of the abdomen was ordered. CT revealed an image compatible with invagination of the right lower quadrant of the abdomen and a mass inside the lumen measuring 4x3x3cm. The mass causing invagination was detected during the surgical operation. A segmentary small bowel resection and ileoileal anastomosis was performed. The patient was discharged uneventfully on the postoperative sixth day. The diagnosis of IMT was confirmed histologically and immunochemically.

Inflammatory Myofibroblastic Tumors: Current Update

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate biological potential with a predilection for the lung and abdominopelvic region. IMT represents the neoplastic subset of the family of inflammatory pseudotumors, an umbrella term for spindle cell proliferations of uncertain histogenesis with a variable inflammatory component. IMTs show characteristic fasciitis-like, compact spindle cell and hypocellular fibrous histologic patterns and distinctive molecular features. Imaging findings reflect pathologic features and vary from an ill-defined, infiltrating lesion to a wellcircumscribed, soft tissue mass owing to variable inflammatory, stromal, and myofibroblastic components.

Inflammatory pseudotumor of the liver occurring during the course of hepatitis C virus-related hepatocellular carcinoma treatment: A case report

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Occurrence of IPT of the liver during the course of HCC treatment is rare.

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IPT of the liver may resemble moderately differentiated HCC on dynamic enhanced CT.

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Hepatic IPT may be associated with latent inflammatory reactions to HCV activity despite negative HCV-RNA.

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Hepatectomy should be considered for a hepatic lesion suspected as HCC but may be IPT.

Introduction

Inflammatory pseudotumor (IPT) of the liver is a rare and benign disease that has a good prognosis. It is often difficult to distinguish IPT from hepatic malignancies, such as hepatocellular carcinoma (HCC), because specific clinical symptoms are absent and the diseases’ radiological findings can be similar. IPT is particularly difficult to distinguish from HCC in livers with hepatitis C virus (HCV)-related cirrhosis. We report a case of IPT of the liver that mimicked HCV-related HCC recurrence.

Presentation of case

A 78-year-old asymptomatic Japanese man who had undergone hepatectomy for HCV-related HCCs (moderately differentiated type) in segments 7 and 5 four and a half years previously was referred to our hospital for treatment of a 30-mm enhanced tumor in segment 5 (a typical HCC pattern). The tumor was identified via abdominal dynamic computed tomography (CT) and CT with hepatic arteriography and arterial portography. Thereafter, liver segmentectomy 5 was performed, and the histopathological diagnosis was a 10-mm IPT of the liver. After 1.5 years, magnetic resonance imaging revealed two new enhanced lesions in segment 8, which showed the typical pattern of HCC. Because these lesions grew in size for 3 months, liver segmentectomy 8 was performed for HCC recurrence. Histopathological examination showed that both lesions were HCCs.

Conclusion

HCV-related HCC has a high rate of multicentric recurrence. Our experience suggests that, when a hepatic lesion is suspected to be HCC, surgical resection should be considered for curative treatment and to rule out malignancy, even if the lesion may be an IPT.

Inflammatory Pseudotumor of the Liver with Escherichia coli in the Sputum

Inflammatory pseudotumor is a nonmalignant lesion that mimics malignant lesions and has been reported to occur at various sites throughout the body. Though it has been reported as a reaction to infection, the true etiology of the lesion is unknown. In this report, we present the case of a patient with a liver lesion of unknown origin. Through a series of imaging studies, we were able to observe the locally aggressive nature of this lesion as it rapidly eroded into the lung. Sputum cultures showed growth of E. coli, indicating E. coli infection as a possible etiology of this lesion. Pathology was consistent with inflammatory pseudotumor.

Detection of Epstein-Barr virus in inflammatory pseudotumour of the spleen: a case report

BACKGROUND

Various types of benign and malignant splenic tumours including hemangiomas, lymphagiomas, hamartomas, hemangiosarcomas, malignant lymphomas and metastatic carcinomas share radiological characteristics making it impossible for a physician to determine the definite aetiology of splenic masses noninvasively without histopathological evaluation. It is important that physicians recognize the importance of a careful and continuous follow-up since inflammatory pseudotumours (IPT) are considered to be tumours with an intermediate malignant potential based on their behaviour when they arise in other locations.

METHODS

Our patient, a 60-year-old woman was evaluated using laboratory, gastroscopy, computed tomography and surgical methods. The resected tumour was evaluated using immunohistochemical methods.

RESULTS

The patient presented with weight loss, nausea and vomiting, symptoms lasting over a course of a few months. The splenic mass was found incidentally at the time of work up for gastritis and cholelithiasis. Histologically, the tumour differed from typical splenic architecture being composed of atypical spindle cells with inflammatory elements; numerous plasma cells, macrophages, eosinophils and lymphocytes.

CONCLUSIONS

Although very difficult to diagnose at initial presentation, it is very important for the physician to be aware of the importance of a careful diagnosis since IPT of the spleen are rare and considered to be tumours with an intermediate malignant potential.

Fever of unknown origin and liver mass in a Saudi child

Inflammatory pseudo tumor (IPT) is a rare benign lesion that can occur in any organ in the body. IPT is histologically characterized by the presence of inflammatory cells, especially, plasma cells, spindle-shaped cells, and myofibroblasts. Many cases of IPTs affecting multiple organs in both adults and children have been documented in the literature. Fifty-five cases of hepatic IPTs have been reported in children, and all of them were managed by surgical resection. Limited data are available on IPTs in Arabs. Our aim was to report the case of an 8-year-old Saudi boy who was referred to our hospital with fever of unknown origin since 3 months with associated weight loss and a hepatic mass, and was found to have an IPT of the liver, which was confirmed after surgical resection. 8 years old Saudi boy who presented with fever and liver mass. Ultrasound and MRI abdomen showed heterogeneous liver mass. After surgical resection, his mass histology going with inflammatory pseudo tumor. Following surgical resection his fever subsided. The findings of the present case report show that fever and liver mass in children can be manifestations of a rare disease such as IPT, which should be considered in the differential diagnosis when all investigations are inconclusive. Based on the literature review, surgical excision seems to be the best treatment strategy for this condition. However, the imaging findings, especially the size and location of the mass, must be carefully discussed with the surgical team before the operation.

Retrospective and comparative study of inflammatory myofibroblastic tumor of the liver

BACKGROUND AND AIM

Inflammatory myofibroblastic tumor of the liver (IMTL) is a very rare benign disease with a good prognosis. The study aims to determine the clinical, radiological, and pathological characteristics of IMTL. The diagnosis and treatment strategies were discussed.

METHODS

A total of 11 patients with pathologically confirmed IMTL receiving treatment over a 15-year period were reviewed retrospectively. The analysis included demographics information and pertinent clinical data. Results obtained from patients with hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (IHCC), and metastatic liver cancer (MLC) receiving surgical resection were compared.

RESULTS

In comparison to HCC, IHCC, and MLC, IMTL has an earlier onset (P < 0.001). IMTL patients had significantly lower aspartate aminotransferase (P = 0.003) and higher alkaline phosphatase (P = 0.034) than HCC patients, and higher gamma-glutamyl transpeptidase (P = 0.010) than MLC patients. Increased serum α-fetoprotein level was detected in only one patient. Serum α-fetoprotein was significantly lower in patients with IMTL (P = 0.000) than in those with HCC but not IHCC (P = 0.558) or MLC (P = 0.514). In contrast to elevated serum CA19-9 in patients with HCC/IHCC/MLC, the serum CA19-9 in IMTL cases was generally normal (vs HCC P = 0.008; vs IHCC P = 0.000; vs MLC P = 0.022). In nine IMTL patients, the tumor appeared as a hypoechogenic solid mass on the ultrasonography. In contrast, most patients with HCC, IHCC, or MLC showed hybrid echo. In contrast computed tomography and magnetic resonance imaging, the lesion of IMTL and MLC appeared as peripheral enhancement.

CONCLUSION

Lab tests, imaging features, and patient history are helpful in the differential diagnosis of IMTL from HCC/IHCC/MLC. Surgical resection is curative for IMTL.

Inflammatory myofibroblastic tumor of the thigh: presentation of a rare case and review of the literature

Inflammatory myofibroblastic tumors are uncommon neoplasms; presentation of these tumors in the lower extremities is extremely rare. We present a case of a 47-year-old male with fever, fatigue, and a slow-growing thigh mass. The inflammatory markers were elevated and the MR images showed a well-defined intermuscular lesion with mild heterogeneous enhancement. The lesion was excised and histologic examination was consistent with an inflammatory myofibroblastic tumor. No adjuvant therapy was needed and the patient remained asymptomatic with no evidence of tumor recurrence during the 2 years of follow-up.

Hepatic inflammatory pseudotumor with elevated serum CA19-9 level mimicking liver metastasis from rectal cancer: report of a case

Inflammatory pseudotumor (IPT) of the liver is rare, and differential diagnosis from malignant tumors is difficult. We herein report a case of IPT of the liver with marked elevation of carbohydrate antigen 19-9 (CA19-9). A 72-year-old woman, who underwent low anterior resection for rectal cancer, had low-grade fever and epigastric pain. The patient has well-controlled idiopathic thrombocytopenic purpura (ITP) with steroid maintenance treatment. Abnormal laboratory findings included serum carcinoembryonic antigen of 15.9 ng/mL and CA19-9 up to 14,632 U/mL. Computed tomography revealed a low-density lesion, and magnetic resonance imaging demonstrated a high intensity lesion on T1, T2-weighted, and diffusion-weighted images (55 × 22 mm in the Couinaud's segment 4 of the liver). However, 1 month after the appearance of the symptom, serum level of CA19-9 suddenly decreased to 37 U/mL. The tumor decreased spontaneously to 20 × 10 mm. Seven months later, the tumor had reduced to 18 × 11 mm. With a diagnosis of IPT, the patient remains well without regrowth of the tumor at 1 year follow-up after CA19-9 decrease to normal limits.

Inflammatory Myofibroblastic Tumor of the Liver: A Diagnostic Challenge

Inflammatory myofibroblastic tumor (IMT) is an uncommon myofibroblastic neoplasm that was formerly included within the broad category of inflammatory pseudotumor (IPT). IMT is rarely encountered in the liver. Similar to IMT of other organs, the interchangeable use of the terms IMT and IPT in liver has made the analysis of these lesions difficult. In this review, clinical and pathological features of IMT of the liver are reviewed and the differential diagnosis of IMT is discussed, with emphasis on IPT and the other entities included in this large category. IMT can mimic malignant tumors. There are no known unique diagnostic clinical, laboratory, or radiological features. The definitive diagnosis of IMT depends on careful pathological examination. The histopathological evaluation of hepatic IMT reveals that, the myxoid/vascular pattern is the most frequently observed, followed by, in decreasing frequency, fibrous histiocytoma-like pattern and hypocellular fibrous pattern. In IMT of the liver, anaplastic lymphoma kinase (ALK) expression reliably predicts the presence of an ALK gene rearrangement. The diagnosis of hepatic IMT depends on the dominant histopathological pattern, and the management of the disease is still controversial. IMT of the liver is a distinctive neoplasm of intermediate biological potential, and should be distinguished from the variety of lesions that are included under the broad category of IPT. Therefore, to avoid confusion regarding the true incidence and behavior of hepatic IMT, the term IPT should not be used interchangeably with IMT. The rarity of IMT in liver should not minimize its consideration in the differential diagnosis of liver tumors, especially in patients with tumor markers in normal range.

Inflammatory pseudotumor of the liver: a rare case of recurrence following surgical resection

Inflammatory pseudotumor (IPT) of the liver is a rare, benign lesion that may be mistaken for malignancy. IPTs are difficult to diagnose due to non-specific clinical, laboratory and imaging features. We report the case of a 38-year old Asian male who presented with fatigue, weight loss and hepatomegaly. He was found to have a large hepatic IPT and underwent surgical resection; approximately two and a half years later, he developed acute cholangitis secondary to IPT recurrence. We present the imaging features of hepatic IPT using ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). We also review the literature on the diagnosis and management of this disease. The unique features of this case include the IPT's recurrence following surgical resection, large size and multiple modalities presented.

Clinical features, image findings, and prognosis of inflammatory pseudotumor of the liver: a multicenter experience of 45 cases

Background/Aims

Inflammatory pseudotumor (IPT) of the liver is a rare disease characterized by chronic infiltration of inflammatory cells. However, the clinical characteristics and outcomes of IPT remain uncertain.

Methods

Clinical features, image findings, and outcomes of 55 patients with histologically proven IPT were evaluated.

Results

They consisted of 26 men and 19 women with median age of 65 years. Serum carcinoembryonal antigen and carbohydrate antigen 19-9 levels were normal in 42 patients (93.3%). Enhanced CT scans indicated poorly defined peripheral enhancement (82.5%) at the arterial phase and poorly defined hyperattenuating lesions with internal hypoattenuating areas at the equilibrium phase (77.0%). Gadolinium-enhancement MRI revealed poorly defined peripheral rim-like enhancement (77.8%). Ten patients underwent surgical resection and 35 were treated conservatively with or without antibiotics. No recurrence was noted after surgical resection during follow-up (1 to 48 months). In all patients who received conservative treatment, complete resolution or size reduction was noted during follow-up (1 to 192 months).

Conclusions

CT and MRI provide clues to the diagnosis of IPT in patients with liver masses and normal tumor markers. However, due to the lack of pathognomonic findings, the clinician's suspicion and histological diagnosis are necessary to make an accurate diagnosis of IPT.

Multiple hepatic inflammatory pseudotumours diagnosed after laparoscopic excisional biopsy

Inflammatory pseudotumours (IPTs) may occur in almost every organ of the human body, the liver being the second most frequent organ which is affected. Inflammatory pseudotumours of the liver are rare benign lesions of unknown aetiology, which usually present as solitary liver masses of variable sizes. The differential diagnoses of malignant liver tumours are challenging and they usually require biopsies and histologic examinations. We are presenting the case of a patient with multiple hepatic lesions which mimicked liver metastases. Two percutaneous biopsies were inconclusive. The definitive diagnosis of multiple hepatic inflammatory pseudotumours was made after a laparoscopic exploration with an excisional biopsy of liver lesions and their pathologic evaluation. All lesions disappeared after several months, without any further treatments.

Inflammatory myofibroblastic tumor of the kidney with viral hepatitis B and trauma: A case report

Inflammatory myofibroblastic tumor (IMT) is a rare entity that most commonly involves the lung. However, an IMT of the kidney is extremely rare. The etiology and pathogenesis of IMT remain unknown. The present study describes the case of a 48-year-old female who presented asymptomatically. Imaging investigations revealed a mass in the left kidney and a pathological examination of the nephrectomy specimen revealed an IMT. The patient had a history of trauma in the left hypochondrium 13 years previously and a history of hepatitis B for 20 years. The latter developed into hepatic cirrhosis, hypersplenism and coagulation disorders, which may play have played a significant role in the development of the IMT of the kidney in the present case and also may aid in improving the understanding of the etiology and pathogenesis of IMT of the kidney.

Inflammatory pseudotumour of the spleen: a diagnostic dilemma

Inflammatory Pseudotumour (IPT) of the spleen is an extremely rare benign lesion of the spleen. It presents as a well-circumscribed mass which is usually solitary and composed of foci of inflammatory cells, mainly plasma cells and lymphocytes in a fibroblastic stroma. We report the case of a 24 year old male who complained of pain in the abdomen, with one episode of vomiting. An ultrasound scan of the abdomen and a contrast enhanced abdominal CT scan showed the presence of a cystic lesion in the spleen. Following a splenectomy, however, it was histologically found to be an IPT of the spleen.

Inflammatory pseudotumours in the abdomen and pelvis: a pictorial essay

Inflammatory pseudotumours are uncommonly encountered lesions in the abdomen and pelvis that often present with variable and nonspecific imaging features. They may mimic other more common lesions, including malignancy. Within the appropriate clinical context, inflammatory pseudotumours merit consideration in the differential diagnosis of soft-tissue masses within the abdomen and pelvis. A preoperative diagnosis of inflammatory pseudotumour, established through biopsy, may help to differentiate this benign entity from malignancy. In this article, we reviewed the imaging features of inflammatory pseudotumours of the abdomen and pelvis, including liver, spleen, bowel, retroperitoneum, kidney, bladder, uterus, and adnexa.

A Case of Inflammatory Pseudotumor of the Liver Mimicking Hepatocellular Carcinoma on EOB-MRI and PET

A 71-year-old man was referred to us for investigation of a liver mass and adenomyomatosis of gallbladder. Findings on ethoxybenzyl diethylenetriamine-enhanced MRI (EOB-MRI) led to a presumptive diagnosis of a 1.5 cm hepatocellular carcinoma (HCC) in the right posterior lobe of the liver. Transcatheter arterial chemoembolization and radiofrequency ablation of the tumor were attempted. After 2 months, CT scan and EOB-MRI showed that the tumor had enlarged to 3 cm. Positron emission tomography (PET) confirmed abnormal metabolic activity with a high standardized uptake value of 7.3 in the lesion. These findings could indicate malignancy such as well-differentiated HCC or cholangiocarcinoma or a benign lesion such as hepatic abscess. Histopathological examination of a liver biopsy revealed a granuloma with many inflammatory cells, leading to a diagnosis of inflammatory pseudotumor of the liver. We report a rare case of hepatic inflammatory pseudotumor with enhancement on EOB-MRI and increased uptake on PET, mimicking HCC.

Adult intestinal intussusception caused by an inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumor (IMT), which usually affects young adults and children, is a solid neoplastic mesenchymal proliferation composed of myofibroblastic spindle cells admixed with inflammatory infiltrates. Numerous extrapulmonary sites of these tumors have been found, but intestinal IMT is rare, especially in elderly patient. Its diagnosis is recognized as difficult because the patients usually do not have a specific symptom. Here, we present the case of a 79-year-old man with an IMT that caused small intestinal intussusception, which was diagnosed by abdominal ultrasonography. We review the literature on IMT and specially focus on the diagnostic modalities for this disease.

Inflammatory pseudotumor of the spleen: A case report and review of published cases

Inflammatory pseudotumor of the spleen (IPTS) is an extremely rare condition. To the best of our knowledge, only ∼113 cases have been reported in the literature since the first 2 cases were reported in 1984. The present study reports the case of an IPTS in a 72-year-old male patient. The splenic tumor was identified incidentally 1 year prior to the patient being admitted to the Second Affiliated Hospital of Dalian Medical University (Dailan, China). There were no specific clinical symptoms. The initial diagnosis was of splenic lymphoma based on the pre-operative radiological findings. However, the patient underwent a splenectomy and the final pathological diagnosis of IPTS was declared. The present study also highlighted the difficulty of forming accurate pre-operative diagnoses, even when using modern imaging techniques. A partial resection of the spleen or splenectomy was considered to be the required treatment to form a definitive diagnosis and exclude malignancy. The prognosis of IPTS is generally considered to be favorable following splenectomy. The clinical and pathological features of previously reported cases are also briefly reviewed in the present study to aid in improving the accuracy of the diagnosis of this rare disease.

Primary inflammatory myofibroblastic tumor of the stomach in an adult woman: a case report and review of the literature

Inflammatory myofibroblastic tumor has been defined as a histologically distinctive lesion with uncertain behaviour. The term inflammatory myofibroblastic tumor more commonly referred to as "pseudostumor ", denotes a pseudosarcomatous inflammatory lesion that contains spindle cells, myofibroblasts, plasma cells, lymphocytes and histiocytes. It exhibits a variable biological behavior that ranges from frequently benign lesions to more aggressive variants. Inflammatory myofibroblastic tumor mostly occurs in the soft tissue of children and young adults, and the lungs are the most commonly affected site, but it has been recognized that any anatomic localization can be involved. Inflammatory myofibroblastic tumors in adults are very rare, especially in the stomach. We present a case of a 43-year old woman with primary inflammatory myofibiroblastic tumor in the stomach and a review of the literature.

Inflammatory pseudotumors mimicking intrahepatic cholangiocarcinoma of the liver; IgG4-positivity and its clinical significance

BACKGROUND

Inflammatory pseudotumor (IPT) of the liver is a benign condition with a good prognosis. However, it is difficult to distinguish clinical and radiological findings of IPT from those of malignancies. The aims of this study are to determine the clinical, radiological, and pathological characteristics, particularly relating to the role of the autoimmune mechanism in the development of inflammatory pseudotumours (IPTs) of the liver, and to suggest appropriate diagnostic and therapeutic strategy.

STUDY DESIGN

The clinical, diagnostic, and pathological characteristics including IgG4 immunohistochemical stain and follow-up data of 22 IPT patients were retrospectively analyzed.

RESULTS

The patients were 16 men and 6 women with a mean age of 59 years. Fifteen patients (68.2%) had associated biliary diseases. Of the 16 patients treated conservatively, the masses completely resolved in 10 patients, and reduced in size in 5 patients within the first 6 months. The remaining 6 patients were treated by surgical resection. IgG4 staining of 17 tissue samples from 22 patients were negative, most of the infiltrate being of fibrohistiocytic type, whereas 4 of 5 lymphoplasmacytic cells of dominant tumors show positive staining of IgG4. Although IgG4-related sclerosing cholangitis was mostly of lymphoplasmacytic type, other histological and clinical characteristics were similar in both types of IPTs.

CONCLUSIONS

IPTs of the liver can be diagnosed based on radiological and pathological findings by needle biopsy. Although the lymphoplasmacytic type of IPTs seems to correspond to IgG4-related disease, as assessed by IgG4 immunohistochemical stain, its clinical significance is unknown. Although most IPTs can be resolved with conservative therapy, surgical resection should be considered in cases of uncertain biopsy result, presumed malignant lesion, combination with other pathology, or lack of response to conservative management.

Necrotic hepatocellular carcinoma occurring within an inflammatory pseudotumor-like nodule

Hepatocellular carcinoma (HCC) and inflammatory pseudotumor of the liver (IPL) are often difficult to differentiate before surgery. To date, colocalization of IPL and HCC has not been reported. We experienced a case of necrotic HCC surrounded by IPL-like tissue. The raised levels of alpha-fetoprotein and PIVKA-II declined to within the normal ranges after resection of the tumor. The IPL-like nodule most likely developed as a process of an inflammatory reaction such as abscess formation after the spontaneous destruction of the HCC. Our case is a warning that the presence of a 'pseudotumor' does not rule out the possible simultaneous presence of carcinoma.