Inflammatory myofibroblastic tumor of the liver

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.

Epstein-Barr virus-associated inflammatory pseudotumor variant of follicular dendritic cell sarcoma of the liver: a case report and review of the literature

BACKGROUND

Follicular dendritic cell sarcoma is a rare stromal tumor with no standard treatment. However, some reports have revealed that follicular dendritic cell sarcoma has an inflammatory pseudotumor variant associated with Epstein-Barr virus infection that has a relatively good prognosis. In this report, we present a case of a resected inflammatory pseudotumor variant of follicular dendritic cell sarcoma of the liver, and have reviewed the literature on the clinicopathological, molecular, and genomic features of this tumor.

CASE PRESENTATION

The inflammatory pseudotumor variant of follicular dendritic cell sarcoma originates only in the liver or spleen, causes no symptoms, and is more common in middle-aged Asian women. It has no characteristic imaging features, which partially explains why the inflammatory pseudotumor variant of follicular dendritic cell sarcoma is difficult to diagnose. Pathologically, the inflammatory pseudotumor variant of follicular dendritic cell sarcoma has spindle cells mixed with inflammatory cells and is variably positive for follicular dendritic cell markers (CD21, CD23, and CD35) and Epstein-Barr virus-encoded RNA. On genetic analysis, patients with this tumor high levels of latent membrane protein 1 gene expression and extremely low levels of host C-X-C Chemokine Receptor type 7 gene expression, indicating that the inflammatory pseudotumor variant of follicular dendritic cell sarcoma has a latent Epstein-Barr virus type 2 infection.

CONCLUSIONS

The inflammatory pseudotumor variant of follicular dendritic cell sarcoma is an Epstein-Barr virus-associated tumor and a favorable prognosis by surgical resection, similar to Epstein-Barr virus-associated gastric cancer.

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 Liver Masquerading as Focal Nodular Hyperplasia in a Patient with Non-Cirrhotic Portal Hypertension and Biliary Pancreatitis

Inflammatory myofibroblastic tumor (IMT) is a rare lesion of undetermined pathogenesis characterized by proliferation of spindled myofibroblast cells in a collagenized inflammatory background. It is usually benign but may show local infiltration or, in rare cases, metastasis. IMT has been observed in almost all solid organs; however, involvement of liver is exceptional. Its symptoms and radiological findings can mimic malignancy and pose diagnostic difficulties. The authors report the case of a 43-year-old woman with non-cirrhotic portal hypertension and gall stone induced acute pancreatitis having a mass in the right lobe of the liver which was initially diagnosed as focal nodular hyperplasia on imaging but proved to be inflammatory myofibroblastic tumor on pathological and immunohistochemical examination. The lesion resolved with conservative management without the need for surgical intervention.

Inflammatory myofibroblastic tumor of the bladder - an unexpected case coexisting with an ovarian teratoma

Inflammatory myofibroblastic tumors (IMTs) mainly occur in children and young adults, usually in the first two decades of life. IMT-type tumors belong to neoplasms of an intermediate biologic potential with considerable rate of local recurrence and in some cases that able to create metastases. Presented case is the first IMT coexisting with the other neoplasm. In our paper we are going to present a peculiar case of an IMT of the bladder coexisting with an ovarian teratoma, and to discuss its pathogenesis, histological picture and differential diagnosis. A 19-year-old female was admitted to the Gynecological Department and during the surgery, two independent, non-adjacent tumors were found. To settle the diagnosis, a FISH examination with the ALK1 break apart probe was carried out. It confirmed the rearrangement of the chromosome 2p23. Morphologic and immunophenotypic similarities between an IMT and other malignant tumors of the bladder may lead to diagnostic errors and an unnecessary radical cystectomy as a result. The therapy of choice is only total excision of the tumor.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1937487606122622.

Pseudosarcomatous myofibroblastic proliferation of the urinary bladder: a rare entity

Pseudosarcomatous myofibroblastic proliferations are very unusual entities of unknown etiology. Despite its benign nature, this entity can easily be misdiagnosed (both clinically and histologically) as a malignant neoplasm. Hereby, we report a case of a 15-year-old woman who presented to our hospital with a broad-based polypoid mass located in the left posterior wall of the urinary bladder. The patient underwent a transurethral resection of the lesion. Morphologic and immunohistochemical findings suggested the diagnosis of pseudosarcomatous myofibroblastic proliferation. The patient is free of recurrence 5 years after surgery.

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 angiomyolipoma of the liver: a rare hepatic tumor

Angiomyolipoma (AML) is a rare mesenchymal neoplasm of the tumor, composed of a varying heterogeneous mixture of three tissue components: blood vessels, smooth muscle and adipose cells. Hepatic AML may demonstrate a marked histological diversity. We herein present one case of hepatic AML exhibiting prominent inflammatory cells in the background, which happened in a 61-year-old Chinese female patient, without signs of tuberous sclerosis. Histologically, the striking feature was the infiltration of numerous inflammatory cells in the background, including small lymphocytes, plasma cells, and eosnophils. The tumor cells were spindled and histiocytoid in shape, with slightly eosinophilic cytoplasm, and arranged along the vessels or scattered among the inflammatory background. Sinusoid structure was obviously seen in the tumor. Mature adipocytes and thick-walled blood vessels were focally observed at the boundaries between the tumor and surrounding liver tissues. The tumor cells were positive immunostaining for HMB-45, Melan-A, and smooth muscle actin. The inflammatory AML should be distinguished from other tumors with inflammatory background such as inflammatory myofibroblastic tumor and follicular dendritic cell tumor and deserves wider recognition for its occurrence as a primary hepatic tumor.

[Guidelines for management of localized inflammatory myofibroblastic tumours in children]

BACKGROUND AND METHODOLOGY

The paediatric rare tumours group from the Société française des cancers de l'enfant makes syntheses and guidelines for diagnosis and treatment for localized paediatric inflammatory myofibroblastic tumours according to international articles.

MAIN UPDATING

All ages are concerning. Localizations are ubiquitous, more frequently in the superior and inferior airway. Histology showed a majority of fusiform cells, corresponding to myofibroblastic cells and an inflammatory infiltrate. Inflammatory myofibroblastic tumour diagnosis should only be confirmed in the absence of sarcoma molecular markers.

CONCLUSIONS

Distinction between inflammatory myofibroblastic tumour and sarcoma is essential due to the different care. The curative treatment of inflammatory myofibroblastic tumour consists on surgery with before or after corticotherapy. In case of unresectability, chemotherapy may be helpful to avoid mutilating surgery.

Inflammatory angiomyolipomas of the liver: a clinicopathologic and immunohistochemical analysis of 5 cases

Hepatic angiomyolipoma (AML) may demonstrate a marked histologic diversity. We report 5 cases of hepatic AML exhibiting prominent inflammatory cells in the background (inflammatory AML). The patients were 4 females and 1 male, with age ranged from 21 to 48 years (mean, 39.2 years). Three tumors were in the left lobe and 2 in the right lobe. The tumor size was from 5.5 to 10 cm in the greatest dimension (mean, 7.46 cm). No patient had clinical features of tuberous sclerosis. Histologically, the striking feature was the infiltration of numerous inflammatory cells in the background of the tumors, including small lymphocytes, plasma cells, and histiocytes. The percentage of tumor area with heavy inflammatory infiltration was more than 50% in all cases. The myoid cells were spindled and epithelioid in shape, with eosinophilic or clear cytoplasm, and were arranged in fascicles and clusters. Scattered adipose cells and sinusoidal and thick-walled blood vessels were variably present in all tumors. Focal trabecular arrangement was present in 2 of the 5 tumors. There was no nuclear atypia, and mitotic figures were rare. The myoid cells were diffusely positive for vimentin, smooth muscle actin, and HMB-45 in all cases. All patients showed no evidence of disease after the initial surgical excision during a follow-up period from 3 to 9 years. The inflammatory AMLs should be distinguished from other tumors with inflammatory background such as inflammatory myofibroblastic tumor and follicular dendritic cell tumor.

Pediatric inflammatory myofibroblastic tumor of the trachea: a case report and review of the literature

Inflammatory myofibroblastic tumors (IMTs) are relatively rare entities of a distinct histologic appearance and benign clinical course. Although these lesions have been described in virtually every anatomic location, there are few documented reports with tracheal localization. We add to the short list of pediatric IMTs of the trachea, a 13-year-old boy that was referred to our pediatric respiratory unit for evaluation of his respiratory distress. In particular, we describe the clinical and pathologic features of this patient and present a review of all reported lesions in the available literature.

Inflammatory pseudotumor associated with Mycobacterium tuberculosis infection

BACKGROUND

Inflammatory pseudotumor is a relatively rare entity; originally identified in the lung, it has been described in multiple extrapulmonary anatomic locations.

CASE REPORT

We report on the unusual case of an inflammatory pseudotumor associated with Mycobacterium tuberculosis infection, which was initially mistaken for a renal malignancy both in clinical and radiological settings. We additionally present three brief reviews concerning: (1) infectious agents postulated to induce morphological changes of an inflammatory pseudotumor; (2) mycobacterial pseudotumors; and (3) distinction from inflammatory myofibroblastic tumors of the renal pelvis.

CONCLUSIONS

The present case highlights the diagnostic importance of PCR-based detection of mycobacterial DNA in granulomatous tissue responses. It is of crucial importance that clinicians are aware of this unusual manifestation of mycobacterial infection to ensure that pertinent laboratory evaluation is employed and appropriate treatment is administered in order to avoid potential clinical implications.

Pseudosarcomatous myofibroblastic lesion of the urinary bladder: a rare entity posing a diagnostic challenge and therapeutic dilemma

BACKGROUND

Pseudosarcomatous myofibroblastic lesions of the urinary bladder are relatively rare entities of an uncertain pathogenesis and benign indolent nature.

CASE PRESENTATION

We present an extremely rare case of an ALK-1-positive pseudosarcomatous myofibroblastic lesion of the urinary bladder, which was initially misinterpreted as a low-grade leiomyosarcoma of myxoid subtype on histologic examination owing to prominent atypia, high mitotic activity, abnormal mitotic figures and infiltration of the bladder wall. Although the histologic features were suggestive of a sarcoma, the correct diagnosis was finally established and radical surgical treatment was subsequently avoided. The patient is currently free of disease without any evidence of tumor recurrence or metastasis at 3 years post-operatively.

CONCLUSION

The key differentiating point rests in distinguishing the aforementioned mass forming lesion from the myxoid subtype of low-grade leiomyosarcoma in order to avoid unnecessary radical therapy.

Splenic inflammatory pseudotumor (inflammatory myofibroblastic tumor)

We report a case of a splenic inflammatory pseudotumor (myofibroblastic tumor) in a 43-year-old man with a 5-year history of chronic bronchitis and sleep apnea syndrome. The patient was hospitalized because of a screen-detected splenic mass lesion. His sputum cultures revealed Mycobacterium avium complexes on only one occasion. Imaging studies revealed a 7 cm solitary tumorous lesion, and differential diagnoses of splenic hamartoma, hemangioma, lymphoma, and angiosarcoma were obtained from the radiologist. A splenectomy followed by pathological investigations was performed. By histology, the lesion contained fibroblastic or myofibroblastic spindle cell proliferations, accompanied by variable degrees of inflammatory cell infiltration. Ziehl-Neelsen staining did not reveal acid-fast bacteria. Immunohistochemically, the fibroblastic or myofibroblastic spindle cells were positive for vimentin, human smooth muscle actin, and muscle actin, but negative for desmin, CD8, CD21, CD23, CD35, p80, Epstein-Barr virus LMP, and human herpesvirus type 8. The infiltrating lymphoid cells demonstrated a nonneoplastic pattern. The results of in situ hybridization for Epstein-Barr virus encoded RNA were negative. The postoperative course was uneventful and he has had no recurrence in 22 months. His sleep apnea syndrome and chronic bronchitis have resolved spontaneously since the splenectomy.