Kupffer cells in hepatocellular adenomas.

Hepatocellular adenomas are usually visualized as defects on technetium-99m-sulfur colloid liver scans, a fact which has been attributed to the absence of phagocytic Kupffer cells in the tumors. To determine whether this is true, seven hepatocellular adenomas were subjected to immunoperoxidase staining for lysozyme, a marker of mononuclear phagocytes. The Kupffer cells were counted in the tumors and surrounding non-neoplastic liver. All hepatocellular adenomas studied were found to contain Kupffer cells. Three tumors had fewer Kupffer cells than the surrounding liver. Three had about the same number as the surrounding liver, and one had more Kupffer cells than the non-neoplastic liver. Thus, the lack of phagocytosis of colloid in liver scans is probably due to something other than a deficiency of Kupffer cells in the hepatocellular adenomas.

Hemangioma of the liver: heterogeneous appearance on T2-weighted images.

We reviewed the gross photographs of 19 patients with hemangioma of the liver. On cut sections, all 19 tumors were inhomogeneous. In 17 cases (89%) there were areas of predominantly central fibrosis. Lobulations were present in 10 cases (53%). Areas of thrombosis (nine cases), calcification (four cases), and hemorrhage (four cases) were also present. We also reviewed 15 hemangiomas of the liver in 12 patients studied by MR imaging. Gross photographs and MR scans were available in three hemangiomas, thus allowing direct radiologic-pathologic correlation. Twelve (80%) of the hemangiomas were inhomogeneous on T2-weighted images and three (20%) were homogeneous. Other characteristics were sharp margins in all 15 cases (100%), lobulations in 11 cases (73%), peripheral location in 10 cases (67%), and internal septations in four cases (27%). We concluded that (1) hemangiomas of the liver are frequently inhomogeneous on cut sections; (2) heterogeneity in T2 images is commonly seen and should not exclude hemangioma; and (3) other signs, such as sharp margins, lobulated contour, and peripheral location, may be helpful in the MR diagnosis of hemangioma of the liver.

Accumulation of technetium-99m sulfur colloid by hepatocellular adenoma: scintigraphic-pathologic correlation.

It is currently believed that hepatocellular adenoma is photon deficient on technetium-99m sulfur colloid scintigraphy because these tumors lack Kupffer cells. In a retrospective review of 13 pathologically proven cases of hepatocellular adenoma with technetium-99m sulfur colloid scintigrams, Kupffer cells were present in all 13 cases. We observed uptake of the radiocolloid by the hepatocellular adenoma in three cases (23%), and there were no histologic differences between the tumors with uptake and the ones without it. We conclude that the currently accepted reason for the lack of technetium-99m sulfur colloid uptake within hepatocellular adenoma is incorrect, and an explanation other than a lack of Kupffer cells is responsible for the photon-deficient appearance in the majority of cases of hepatocellular adenoma. Further, because hepatocellular adenoma may have technetium-99m sulfur colloid uptake in a significant percentage of cases, it should be added to focal nodular hyperplasia in the differential diagnosis of a hepatic mass with uptake by technetium-99m sulfur colloid.

Compression pain in a diver with intraosseous pneumatocysts.

A 30-yr-old diver experienced pain in the area of the sacroiliac joint during the descent phase of air diving to less than 10 ATA. Computed tomography of the pelvis demonstrated two gas-filled cysts within the ilium. The mechanism by which this lesion causes pain is discussed and reports of gas within bone are reviewed.