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

So-called inflammatory myofibroblastic tumour: a proliferative lesion of fibroblastic reticulum cells?

The term inflammatory pseudotumour was originally used in a generic fashion for any lesion which simulated a neoplastic condition at a clinical, macroscopic and microscopic level but which was thought to have an inflammatory/reactive pathogenesis. In more recent times, the term has been employed in a more restrictive sense for a mass lesion characterized microscopically by the proliferation of a spindle cell component against a heavy inflammatory infiltrate of mixed composition but usually with a predominance of mature lymphocyte and plasma cells. The spindle cell component has generally been regarded as being of mesenchymal nature and having morphological and phenotypical features consistent with fibroblasts or myofibroblasts, the latter cell being clearly preferred over the former in the more resent reports. The term inflammatory myofibroblastic tumour (IMFT) is the one currently favoured, which proposes the myofibroblastic nature of the process. It is the purpose of this review to bring forth some evidence that the neoplastic spindle cell component of IMFT may be instead derived from the subtype of cells of the accessory immune system that have been variously called fibroblastic reticulum cells, myoid cells, and dictyocytes.

Imaging of follicular dendritic cell tumours of the liver

Follicular dendritic cell tumour of the liver is a recently recognized entity. To date, only two cases have been described, both in the pathology literature. Histologically, it resembles an inflammatory pseudotumour and immunohistochemical and ultrastructural studies are required for its diagnosis. The ultrasound, computed tomography and angiographic features of two cases of follicular dendritic cell tumour of the liver are described in detail. One of the patients had multiple recurrences of this tumour. The imaging features are very similar to those of hepatocellular carcinoma. As follicular dendritic cell tumour is considered to be of low-grade malignant potential, in contrast to the dismal prognosis for hepatocellular carcinoma, it is important to be able to accurately distinguish between the two types of tumour prior to initiating definitive therapy.

Hepatic hilar inflammatory pseudotumor mimicking cholangiocarcinoma with cholangitis and phlebitis--a variant of primary sclerosing cholangitis?

Inflammatory pseudotumor (IPT) of the liver is rare. We present a case of hepatic IPT mimicking cholangiocarcinoma in which the tumor was located at the left porta hepatis. The patient was a 64-year-old man in whom abnormal liver function test results had been noted incidentally during an annual health checkup in 1993: the patient declined to go to the hospital for further examination. At the annual health checkup the following year, abnormal liver function test results were noticed again, and this time he did go to a hospital, where a hepatic mass was found. Laboratory test results were unremarkable. Based on the location of the lesion and the findings of a variety of imaging modalities, such as ultrasound and computed tomography examination, the lesion was preoperatively diagnosed as hilar cholangiocarcinoma and was surgically resected. Pathologic examination of the resected lesion, however, revealed that it was not a true tumor but an inflammatory pseudotumor with marked destructive and sclerosing cholangitis mimicking primary sclerosing cholangitis (PSC) and obliterative phlebitis. Since the location and features of the tumor in the present case are very pertinent to the relationship between IPT and PSC, we describe its clinical and histologic features and discuss the findings in relation to PSC in the context of our literature review.