Inflammatory myofibroblastic tumor of the liver mimicking an infiltrative malignancy in computed tomography and magnetic resonance imaging with Gd-EOB

Primary Hepatic Inflammatory Myofibroblastic Tumor With Synchronous Primary Squamous Cell Lung Cancer in an Elderly Woman

The hepatic inflammatory myofibroblastic tumor is a spindle cell tumor of the liver that originates from the mesenchymal tissues. It is a rare benign tumor with the potential to degenerate into a malignant and invasive tumor. It can occur anywhere in the body with the most common sites being the lung, mesentery, and omentum. The most common types are myxoid, vascular pattern, fibrous, or hypocellular fibroid type. Immunohistochemistry staining often indicates vimentin, muscle-specific actin, smooth muscle actin, and cytokeratin. These tumors are positive for CD 68 abundant histiocytes but negative for S100. Half of the inflammatory myofibroblastic tumors contain a clonal cytogenetic aberration that activates the ALK gene expression. We present a rare case of HIMT in an elderly female with active primary squamous lung cancer.

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.

Inflammatory myofibroblastic tumor of the liver: A case report and review of literature

BACKGROUND

Inflammatory myofibroblastic tumors of the liver (IMTL) are extremely rare neoplasms and very little is known about their clinical presentation, pathogenesis, and biological behavior. Due to their absolute rarity, it is almost impossible to obtain a definite diagnosis without histological examination. Because of their intermediate biological behavior with the risk for local recurrence and metastases, surgical resection is recommend whenever IMTL is suspect.

CASE SUMMARY

We herein present a case of an otherwise healthy 32-year-old woman who presented with intermittent fever, unclear anemia, malaise and right flank pain 4 mo postpartum. The liver mass in segment IVa/b was highly FDG avid in the positron emission tomography-computed tomography. Hepatic resection was performed achieving a negative resection margin and an immediate resolution of all clinical symptoms. Histological analysis diagnosed the rare finding of an inflammatory myofibroblastic tumor of the liver and revealed cytoplasmic anaplastic lymphoma kinase expression by immunohistochemistry. Twelve months follow-up magnetic resonance imaging showed no recurrence and no metastases in the fully recovered patient.

CONCLUSION

IMTLs are extremely rare and difficult to diagnose. Due to their intermediate biological behavior, surgical resection should be perform whenever feasible and patients should be followed-up in order to detect recurrence and metastasis as early as possible.

Hepatic inflammatory pseudotumor presenting in an 8-year-old boy: A case report and review of literature

Hepatic inflammatory pseudotumors are uncommon benign lesions. Accurately diagnosing hepatic inflammatory pseudotumor can be very challenging because the clinical presentation and radiological appearances are nonspecific and cannot be certainly distinguished from malignant neoplastic processes. Herein, we present a case of hepatic IPT in an 8-year-old boy who presented to clinic with a 3-mo history of a tender hepatic mass, fever of unknown origin, and 9-kg weight loss. The physical examination was notable for tender hepatomegaly. Laboratory investigations were notable for a normal hepatic profile and elevated erythrocyte sedimentation rate and C-reactive protein. A T2-attenuated magnetic resonance imaging scan of the abdomen showed a 4.7 cm × 4.7 cm × 6.6 cm, contrast-enhancing, hyper-intense, well-defined lesion involving the right hepatic lobe. In view of the unremitting symptoms, tender hepatomegaly, thrombosed right hepatic vein, nonspecific radiological findings, and high suspicion of a deep-seated underlying infection or malignancy, a right hepatic lobectomy was recommended. Microscopically, the hepatic lesion exhibited a mixture of inflammatory cells (histiocytes, plasma cells, mature lymphocytes, and occasional multinucleated giant cells) in a background of dense fibrous tissue. Immunohistochemically, the cells stained negative for SMA, ALK-1, CD-21 and CD-23, diffusely positive for CD-68, and focally positive for IgG4. The final histopathological diagnosis was consistent with hepatic IPT. At the postoperative 4-mo follow-up, the patient was asymptomatic without radiological evidence of recurrence.