Inflammatory myofibroblastic tumor of the liver

A case of multiple inflammatory hepatic pseudotumor protruding from the liver surface after colonic cancer

INTRODUCTION

Inflammatory hepatic pseudotumor (IHPT) is an important benign liver disease because it is difficult to clinically and radiologically distinguish from malignant tumors.

PRESENTATION OF CASE

Here, we describe a case of a 67-year-old male patient diagnosed with multiple inflammatory hepatic pseudotumors. The patient had undergone left hemicolectomy for descending colonic cancer (T3 N0 M0 stage IIA) 2 years prior. He underwent segment 6 and segment 7 partial hepatectomy because of suspected liver metastasis. The patient had an unremarkable postoperative course and was discharged 7days after surgery. Marked infiltration of inflammatory cells was observed on histological examination. The patient was finally diagnosed with IHPT of the fibrohistiocytic type.

DISCUSSION

Repeated imaging studies over 1 month showed the spontaneous regression of the hepatic tumors. Therefore, knowledge regarding this condition is necessary to allow for treatment, even in the absence of experience. During examination, it may be important to ascertain lesion size. Moreover, percutaneous needle biopsy and follow-up examinations are necessary for cases of suspected IHPT.

CONCLUSION

Hepatectomy should be considered if the lesion is suspected to be an IHPT.

The analysis of enhancement pattern of hepatic inflammatory pseudotumor on contrast-enhanced ultrasound

OBJECTIVE

The aim of this study was to assess the role of contrast-enhanced ultrasound (CEUS) in the characterization of hepatic inflammatory pseudotumor (IPT).

METHODS

We retrospectively reviewed 36 cases of histopathologically diagnosed IPT. Nodule enhancement appearances during the arterial, portal, and delayed phases were defined as hyperenhancement, isoenhancement, hypoenhancement, and non-enhancement compared with the surrounding liver parenchyma. Statistical analysis was performed by the one-way ANOVA and χ (2) tests.

RESULTS

Among total 36 cases, 7 nodules were absent of contrast enhancement during all three phrases on CEUS. Twenty-nine nodules appeared different forms of enhancement in arterial phase. Diffuse homogeneous hyperenhancement, diffuse heterogeneous hyperenhancement, peripheral rim-like enhancement, and diffuse iso-enhancement were found in 10, 12, 5, and 2 of the nodules, respectively. Twenty-five nodules showed hypoenhancement in portal and delayed phases. Four nodules showed contrast washed out synchronously with normal liver parenchyma. The median time to enhancement, median time to peak, and median time to wash out of the nodules were 17 s (range 11-28 s), 23 s (range 14-42 s), and 45 s (range 23-100 s), respectively. No statistical significant differences were found in the above parameters of nodule enhancement and proportion of enhancement patterns when dividing the nodules into subgroups by nodule size.

CONCLUSION

IPT displays a variety of enhancement patterns due to pathological changes in the course of disease progression. Some characteristics on CEUS may be helpful in the differential diagnosis of IPT.

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.

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.

Sonazoid-enhanced ultrasonography and Ga-EOB-DTPA-enhanced MRI of hepatic inflammatory pseudotumor: a case report

A liver neoplasm was found in a 63-year-old man with alcoholic liver disease. Sonazoid-enhanced ultrasonography (US) showed that the neoplasm was isoechoic at the early vascular phase and hypoechoic at the post-vascular phase. Gadolinium ethoxybenzyl-diethylenetriamine-enhanced magnetic resonance imaging (MRI) showed that the neoplasm was hypointense at the hepatobiliary phase. We suspected that it was a malignant tumor. By needle biopsy, however, the neoplasm was diagnosed as an inflammatory pseudotumor (IPT). We encountered a rare case of hepatic IPT, the differential diagnosis of which was difficult to distinguish from malignant tumor. Here, we report new US and MRI findings of hepatic IPT.

Diagnostic puzzle of inflammatory pseudotumor of the urinary bladder: a case report with brief literature review

Inflammatory pseudotumor of the urinary bladder is a rare reactive proliferation with a clinical presentation similar to malignant neoplasms. We present the case of a 35-year-old woman who presented with left lower quadrant pain and gross hematuria. A diagnosis of cystitis glandularis was initially considered; however, the symptoms did not resolve following transurethral resection. Subsequently, a partial cystectomy was performed after malignancy was excluded based on intraoperative frozen sections. Further histopathological evaluation confirmed the diagnosis of inflammatory pseudotumor.

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.