Vascular invasion by hepatic inflammatory pseudotumor. A clinicopathologic study.

BACKGROUND: Unusual lesions composed of fibrous tissue, lymphocytes, histiocytes, and plasma cells, called inflammatory pseudotumors (IPT), are being increasingly recognized in many organs and tissues. A hepatic IPT extending into the inferior vena cava has never been reported before to the authors' knowledge. The patient in this study underwent liver resection with cardiopulmonary bypass and circulatory arrest to excise the IPT. METHODS: The tissue was studied extensively using histologic, immunohistologic, flow cytometric, and gene rearrangement analysis and electron microscopic methods. RESULTS: On gross examination, the large hepatic tumor resembled a malignancy invading the vena cava. Microscopically, a mixture of T-lymphocytes, B-lymphocytes, and plasma cells were scattered throughout the tumor. DNA flow cytometry did not reveal aneuploidy suggestive of neoplasia. Genetic analysis of the immunoglobulin and T-cell receptor genes did not detect evidence of clonal expansion of B-cells or T-lymphocytes. CONCLUSIONS: This experience with the vascular invasive and biliary obstructive nature of IPT and the difficulty in diagnosing it before or during surgery underscores the potentially adverse impact of this lesion on patients. The authors believe that an aggressive approach should be taken when evaluating and treating hepatic masses, even though they may later be confirmed as being IPT.

The in vivo performance of 250 internal fixation devices: a follow-up study.

The in vivo performance of 250 retrieved internal fixation plates was evaluated. The corrosion characteristics and metallurgical properties of each implant were assessed and correlated with respective clinical performance. Screw-plate interface corrosion and screw surface corrosion were graded; Rockwell hardness, grain size, thin inclusion content, and heavy inclusion content measurements were made. The devices studied included 169 bone plates, 59 Richards type hip screw-plates and 22 Jewett type hip nail-plates. The devices remained in situ for an average of 26.3 months, with in situ periods ranging from 1 to 192 months. The majority of the plates (50.4%) were removed due to cause-related reasons, while the remaining devices (49.6%) were removed on a routine asymptomatic basis. The primary symptomatic removal reasons consisted of implant related pain, nonunion or malunion, infection, loosening and implant breakage. Upon stereomicroscopic examination, 89% of all plates exhibited some degree of interface crevice corrosion, and 88% of all screws exhibited some degree of surface corrosion. Statistical analysis of corrosion gradings and metallurgical data revealed significant correlations between the two. As was suggested in our previous study of a limited number of implants, this study demonstrates that stricter manufacturing standards for metallurgical properties would serve to enhance corrosion resistance and improve the in vivo performance of stainless steel internal fixation devices. It is also suggested that the routine removal of all internal fixation plates after fracture healing has been achieved would reduce the occurrence of symptomatic complications, such as implant breakage, implant loosening and implant related pain.