solitärer fibröser Tumor der Leber
Hepatic solitary fibrous tumors (hepatic SFTs) are rare mesenchymal tumors.
Epidemiology
Fewer than 60 cases have been reported in the literature. Female predominance (~70%). There is a mean age of 52 years at presentation, but a wide range of incidence (16-84 years).
Clinical presentation
If the patient is symptomatic at all, the presentation is usually mild and nonspecific, including abdominal pain, bloating, dyspepsia.
Hypoglycemia has been reported in some patients, presumably a paraneoplastic syndrome.
Pathology
Microscopic appearance
These tumors demonstrate high cellular proliferation of spindle cells arranged in a storiform pattern.
Immunophenotype
- CD34: positive
- vimentin: positive
- Bcl-2: positive
- SM-actin: negative
Radiographic features
A prospective diagnosis of hepatic SFT is not usually possible because imaging features are usually relatively nonspecific. Intratumoral necrosis has been reported in a few lesions. Benign tumors cannot currently be reliably be differentiated from malignant tumors.
CT
- nonspecific enhancing mass
- heterogeneous enhancement has been reported
MRI
- T1: hypointense
- T2: heterogeneous appearance
- T1 C+ (Gd): heterogeneous enhancement, depending on the relative amounts of cellular and collagen components
Nuclear Medicine
- FDG-PET: avid FDG uptake
Treatment and prognosis
Most recorded hepatic SFTs are benign, but it is possible for them to exhibit malignant behavior . Some think that malignant foci may exist in biopsy-benign tumors, and the risk of malignancy is estimated at ~10% .
Given the rarity of the tumor, no standard treatment exists. Partial hepatectomy has been performed for some lesions, given the concern for occult malignancy.
Differential diagnosis
- hepatocellular carcinoma
- metastatic GIST
- hepatic leiomyoma
- hepatic angiomyolipoma
- inflammatory myofibroblastic tumor of the liver
- hemangiopericytoma