| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Case Report |
1 Department of Radiology, Hôpital de Hautepierre, CHU Strasbourg, Avenue
Molière, Strasbourg 67000, France.
2 Department of Pathology, Hôpital de Hautepierre, Strasbourg 67000,
France.
3 Department of Digestive Surgery, Hôpital de Hautepierre, Strasbourg
67000, France.
Received February 3, 2004;
accepted after revision July 22, 2004.
Address correspondence to T. Moser
(moser_th{at}yahoo.fr).
Introduction
 Top Introduction Case ReportDiscussionReferences |
|---|
Hepatic localized fibrous tumors are exceedingly rare, with all descriptions based on one or a few case reports that are not amenable to statistical analysis [3–5]. Fuksbrumer et al. [3] published the most extensive imaging description of hepatic localized fibrous tumors, to our knowledge. In their three-case series, hepatic localized fibrous tumor was characterized as a large solitary lesion appearing heterogeneous on sonography, CT, and MRI.
We present a case of localized fibrous tumor occurring in the liver with radiologic–pathologic correlation and emphasis on the delayed enhancement of the tumor on CT and MRI.
|
TopIntroductionCase ReportDiscussionReferences |
|---|
On admission, blood glucose level was 0.22 g/L (normal range, 0.70–1.1 g/L). Physical examination revealed a huge firm and rubbery mass in the right upper abdominal quadrant. Results of liver function tests were unremarkable. Blood insulin, C peptide, insulin-like growth factor 1, growth hormone, and cortisol were all within normal ranges.
During hospitalization, glycemia was kept to normal through continuous IV infusion of 10% glucose solution and subcutaneous administration of glucagon.
Abdominal sonography (Sonoline Elegra, Siemens) confirmed the presence of a huge mass in the right upper quadrant. It was hyperechoic to the liver parenchyma and contained numerous cystic foci.
Helical CT images (ProSpeed SX Advantage, GE Healthcare) were obtained before (Fig. 1A) and 30 sec (Fig. 1B), 1 min (Fig. 1C), and five min (Fig. 1D) after IV contrast injection. These images showed a well-demarcated, hypodense lesion containing numerous prominent cystic areas. Portions of the lesion enhanced faintly during both the arterial (30 sec) and portal (1 min) phases. However, marked contrast enhancement was seen 5 min after injection. Cystic areas remained unchanged throughout the whole examination. The adjacent right liver lobe was displaced to the left mimicking an extrahepatic origin. However, a single tiny area of the tumor appeared in continuity with segment VII, which favored the hypothesis of a pedunculated hepatic mass.
|
|
|
|
Preoperative workup also included MRI, with MR venography of the inferior vena cava on a 1.5-T scan (Magneton, Siemens). Spoiled gradient-echo T1-weighted sequences with fat suppression were obtained 30 sec, 1 min, and 8 min (Fig. 1E) after injection of gadolinium chelates. In addition, to rule out inferior cava vein obstruction, which would have influenced the surgical procedure, we obtained multiplanar images; these images reinforced the hypothesis of a pedunculated liver mass. Furthermore, the delayed enhancement pattern seen on CT was more conspicuously reproduced.
|
The aforementioned clinical and imaging data suggested a mesenchymal hepatic tumor, and the hypothesis of a fibrosarcoma was raised.
The patient underwent surgery, and the tumor was removed together with part of the segment VII. The hepatic origin was then confirmed, and involvement of other abdominal structures was ruled out. The lesion measured 35 x 20 x 15 cm, weighed 3,900 g, and was partially surrounded by the liver capsule. On cut section, it was whitish and contained numerous cystic foci.
On histology (Fig. 1F), the
tumor was found to be a mesenchymal tumor composed of spindle cells disposed
haphazardly and interspersed with collagen bundles. No conspicuous vessels
were found throughout the tumor. Immunohistochemistry was positive for
vimentin, bcl-2, and CD34 and was negative for vascular (CD31, factor
VIII), epithelial (keratin, epithelial membrane antigen), nervous (S-100
protein), and muscular (desmin and 
-actin) markers. Proliferation index
(MIB-1 cell proliferation marker) was low, ranging from 1% to 2%. Altogether,
these features were diagnostic of a localized fibrous tumor of the liver
[1–6].
|
Immediate follow-up after surgery was uneventful, and glycemia returned to normal range levels.
|
TopIntroductionCase ReportDiscussionReferences |
|---|
Abdominal localized fibrous tumors generally present with vague abdominal complaints or even mild liver function test abnormalities [3–5]. Some patients may even be asymptomatic and the tumor incidentally discovered. Hypoglycemia has been described as a paraneoplastic manifestation for intra- and extraabdominal localized fibrous tumors and can manifest as an inaugural coma as reported here and also by Chithriki et al. [7]. Its mechanism may involve excessive glucose consumption by the tumor, overexpression of insulin receptors, or tumoral production of hypoglycemic factors [1–7]. In our patient, blood insulin and hypoglycemic factor levels were within normal ranges, which favors excessive consumption.
The few reported hepatic localized fibrous tumors reproduced the classic histologic pattern described for the pleural variant [1–5]. It consists of spindle cells tightly packed together and intermingled with collagen fascicles. Most commonly, the cells are disposed haphazardly in an arrangement known as the "patternless" pattern. Furthermore, a varying cellularity is characteristic: It means there are alternating hyper- and hypocellular areas in the same tumor. Staghorn branching and dilated vessels are seen admixed with the cellular proliferation, an aspect known as the hemangiopericytoma-like vascular pattern [1–6]. The latter is rather frequent and was seen in all nine cases reported by Moran et al. [4], who described the largest series of hepatic localized fibrous tumor to date. However, the hemangiopericytoma-like vascular pattern was absent in the present case. Rather, it was a poorly vascularized tumor with an interstitium that was almost exclusively composed by collagen fibers.
Previously reported hepatic and extrahepatic localized fibrous tumors showed early contrast uptake that was correlated with the prominent vascular structures [1–6]. Fuksbrumer et al. [3] found heterogeneous enhancement with areas of differential uptake and washout, which they believed were possibly related to the varying cellularity. By contrast, the present case showed—on both CT and MRI—a progressive enhancement during the arterial and portal phases that became marked on delayed images. As previously stated, our case lacked the prominent vessels. Its enhancement dynamic is in accordance with a collagen-rich interstitium with a poor vascular network, as has already been shown in the literature for a wide range of fiber-containing lesions [8].
Hepatic localized fibrous tumor should be included in the differential diagnosis of other rare mesenchymal tumors occurring in the liver. When poorly vascularized, as in the present case, localized fibrous tumor may be confused with fibrous tissue–containing sarcomas such as fibrosarcoma and malignant fibrous histiocytoma [1, 9]. Hepatic fibrosarcoma is a rare neoplasm that may attain large size and can also be revealed by hypoglycemia [9]. It is a spindle cell tumor with a collagen-rich stroma that bears closest morphologic and microscopic resemblance to the localized fibrous tumor variant presented herein. However, the lack of herringbone cellular arrangement and the positivity for CD34 seen in our case precluded the diagnosis of fibrosarcoma [9].
In conclusion, localized fibrous tumor is a rare but well-established entity that should be considered in the differential diagnosis for a large, well-demarcated hepatic mass, particularly if clinical manifestations of hypoglycemia are associated. Visualization of progressive contrast enhancement is particularly useful to assess the presence of fibrous tissue, and delayed images should be included in the imaging protocol of such cases.
Acknowledgments
We thank A. Mataoanu for her editorial assistance.
|
TopIntroductionCase ReportDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
