1023 Pictorial Essay Abdominal Complications After Bone Marrow Transplantation in Children: Sonographic and CT Findings Ellen C. Benya,1 2 Carlos J. Sivit, 2 and Ralph R. Quinones2 3 Bone marrow transplantation is Increasingly used in children to treat refractory malignant neoplasms, immunodeficlency syndromes, and hematopoletic and genetic disorders. In preparation for the transplantation, patients receive high doses of chemotherapeutic agents and total-body irradiation to destroy residual malignant cells or dysfunctional marrow and to prevent rejection of the graft. A variety of abdominal and pelvie complications may occur after transplantation because of pancytopenia, the direct toxic effects of the preparative regimen, graft-vs-host disease, or immunosuppression. This essay Illustrates the CT and sonographlc appearances of these complications. Infection Children who have bone marrow transplantation are at increased risk for infections associated with the prolonged neutnopenia and breakdown of mucosal barriers induced by chemotherapy and radiation given before the transplantation. The spectrum includes infectious entenitis, colitis, hepatitis, and rarely abscesses (Fig. 1), which may be due to a variety of viruses, fungi, and bacteria. Neutropenic Colitis Neutropenic colitis is characterized by necrotizing inflammation of the cecum and ascending colon with cecal stasis, distension, and ischemia [1]. This is often accompanied by secondary bacterial infection, along with invasion of the bowel wall and sepsis. Thickening of the cecum and ascending colon occurs also (Figs. 2 and 3A). On sonograms, the bowel wall appears echogenic. Infiltration of penicecal fat and appendiceal enlargement may also be present (Fig. 3B). Pneumatosis Intestinalis Pneumatosis intestinalis is the presence of submucosal or subsenosal gas in the gastrointestinal tract (Fig. 4). The cause of this condition after bone marrow transplantation is uncertain; however, it may be the result of bowel ischemia or mucosal destruction related to chemotherapy, irradiation, or infection. Pneumatosis intestinalis may also occur after highdose corticosteroid treatment of graft-vs-host disease. In these patients, pneumatosis intestinalis is usually not associated with bowel necrosis and often resolves with conservative management. Venoocclusive Disease Hepatic venoocclusive disease is characterized by narrowing and occlusion of small intrahepatic veins caused by endothelial inflammation. This condition can be progressive and fatal. The most specific associated imaging finding is hepatofugal (Fig. 5) on bidirectional (Fig. 6) portal venous flow on Received May 6, 1993; accepted after revision July 13, 1993. 1Departrnents of Diagnostic Imaging and Radiology, Children s National Medical Center, 111 Michigan Ave., NW., Washington, DC 20010 and the George Washington University School of Medicine and Health Sciences, Washington, DC 20037. Address correspondence to E. C. Benya at Children s National Medical Center. 2Department of Pediatrics, Children s National Medical Center, 111 Michigan Ave., NW., Washington, DC 20010 and the George Washington University School of Medicine and Health Sciences, Washington, DC 20037. 3Department of Hematology/Oncology, Children s National Medical Center, 111 Michigan Ave., NW., Washington, DC 20010 and the George Washington University School of Medicine and Health Sciences, Washington, DC 20037. AJR 1993;161 :1023-1027 0361-803X/93/1615-1023 American Roentgen Ray Society
Fig. 1.-9-year-old child with a perirectal abscess. CT scan of pelvis shows a gas-contaming abscess (arrows) treated by incision and drainage. Fig. 2.-14-year-old child with neutropenic colitis. CT scan of lower part of abdomen shows thickening of easel wall (arrows). Patient was treated conservatively with subsequent improvement in symptoms as neutropenla resolved. :- : -i Fig. 3.-9-year-old child with neutropenic colitis. A, Longitudinal sonogram of cecum shows diffuse thickening of bowel wall (arrows). B, Sonogram of adjacent appendix shows enlargement (arrows). With conservative treatment, both cecal wall thickening and appendiceal enlargement resolved as patient s symptoms improved. Fig. 4.-6-year-old child with pneumatosis intestinalls. CT scan of pelvis shows intramural air (arrow) and associated peritoneal fluid (P). Fig. 5.-b-year-old child with hepatic venooccluslve disease. A, Duplex Doppler sonogram obtained before bone marrow transplantation shows normal hepatopetal flow In portal vein. B, Follow-up sonogram obtained after venoocclusive disease developed shows reversal of flow In portal vein. Fig. 6.-14-year-old child with hepatic venoocclusive disease. Duplex Doppler sonogram shows bidirectional flow In portal vein.
AJR:161, November 1993 COMPLICATIONS AFTER BONE MARROW TRANSPLANTATION 1025 Doppler sonognams [2, 3]. Hepatopetal portal venous flow returns when the venoocclusive disease resolves. Other findings include hepatomegaly, thickening of the wall of the gallbladder, ascites, periportal zones of low attenuation (Fig. 7), and an increase in the resistive index of the hepatic artery [3]. Hemorrhagic Cystitis Hemorrhagic cystitis is a frequent complication. It is the result of damage to the mucosa of the bladder caused by cyclophosphamide and its metabolites. The characteristic imaging finding is focal or diffuse thickening of the bladder wall (Figs. 8 and 9). Blood clots on sloughed mucosa may be seen within the bladder lumen (Fig. 10). Graft-vs-Host Disease Graft-vs-host disease occurs in allogenic bone marrow transplantation and is initiated by immunocompetent donor T cells that react against the host s cells. The acute form occurs within the first 100 days after transplantation; the chronic form occurs more than 100 days after transplantation. The clinical grading of the acute form is based on the degree of damage to the skin, gastrointestinal tract, and liven [4]. The imaging appearances of the acute and chronic forms are similar and include focal or diffuse thickening of the bowel wall (Fig. 11), hepatomegaly, and infiltration of mesentenic fat (Fig. 12). An uncommon complication is formation of a stricture and subsequent obstruction of the small bowel (Fig. 13). Lvmnhonroliferative Disorder After Transplantation Lymphoprolifenative disorder occurring after transplantation ranges from polyclonal lymphoid hyperplasia to malignant monoclonal lymphoma. Approximately 90% of cases are due to B cells and 10% to T cells. This disorder is FIg. 7.-15-year-old child with hepatic venoocciusive disease. A, CT scan through upper part of abdomen shows periportal zones of low attenuation (arrows). B, CT scan through pelvis shows ascites (arrows). Fig. 8.-S-year-old child with gross hematuna. Transverse sonogram of bladder shows focal thickening of bladder wall (arrow) due to hemorrhagic cystitis. Fig. 9.-7-year-old child with hemorrhagic cystitis. CT scan through pelvis shows diffuse thickening of bladder wall (arrows). Fig. 1 0.-i 0-year-old child with hemorrhaglc cystitls. Longitudinal sonogram of bladder shows thickening of bladder wall (straight arrows) and residual septa (curved arrow) in bladder from previous blood clots.
1026 BENYAETAL. AJR:161, November 1993 thought to be a sequela of intense or chronic immunosuppressive therapy that is induced by Epstein-Barr virus. It generally develops within 1 year after transplantation. CT scans show abdominal and pelvic lymphadenopathy, penportal zones of low attenuation, hepatomegaly, splenomegaly, and ascites (Fig. 14). Prompt imaging and biopsy are required so that potentially life-saving treatment can be started. Tumor Recurrence Recurrence of leukemia on solid tumors is due to the pensistence of malignant cells despite chemotherapy and innadiation used before transplantation. It may occur at the site of the primary tumor (Fig. 15) on at distant sites (Fig. 16). Recurrence of tumor usually occurs within 2 years after transplantation. Fig. il-s-year-old child with graft-vs-host disease. Fig. i2.-8-year-old child with graft-vs-host A and B, CT scan of pelvis obtained with child in right lateral decubitus position (A) and sono- disease. CT scan through upper part of pelvis gram of right lower quadrant (B) show diffuse thickening of wall of small bowel (arrows). shows linear areas of increased attenuation in mesenteric fat (arrows) caused by edema and inflammation. 1. y- C \..t.:1. #{149}:, A B Fig. 1 3.-Stricture formation associated with graft-vs-host disease. CT scan shows marked distension of small bowel (solid arrows) proximal to stricture with nondilated bowel distal to site of obstruction (open arrow). Fig. 14-2-year-old with lymphoprollferative disease after transplantation. A, CT scan of upper part of abdomen shows periportal zones of low attenuation (arrows). B, CT scan of middle part of abdomen shows ascites (open arrow), pericholecystic fluid (straight solid arrow), and retroperitoneal adenopathy (curved arrows).
AJR:161, November 1993 COMPLICATIONS AFTER BONE MARROW TRANSPLANTATION 1027 Fig. 15.-6-year-old child with recurrent neuroblastoma. A, Initial CT scan of pelvis after bone marrow transplantation shows normal retroperitoneum. B, Follow-up CT scan through same region shows Interval development of retroperitoneal mass (arrows). Pathologic examination showed neuroblastoma. Fig. 16.-S-year-old child with recurrent leukemia. A, Initial CT scan of upper part of abdomen obtained after bone marrow transplantation shows normal-appearing pancreas (arrows). B, Subsequent CT scan obtained after relapse shows diffuse pancreatic enlargement (arrows). A B REFERENCES 1. Teefey 5, Montana MA, Goldfogel GA, Shuman WP. Sonographic diagnosis of neutropenic typhlitis. AJR 1987:149:731-733 2. Brown BP, Abu-Yousef M, Farner R, LaBrecque D, Gingrich R. Doppler sonography: a noninvasive method for evaluation of hepatic venoocclusive disease. AJR 1990:154:721-724 3. Herbetko J, Gngg AP, Buckley AR, Phillips GU. venoocclusive liver disease after bone marrow transplantation: findings at duplex sonography. AJR 1992:158:1001-1 005 4. Sosman J, Hang R, Sondell PM. Etiology and pathogenesis of graftversus-host disease: II. Human studies. In: Johnson FU, Pochedly C, eds. Bone marrow transplantation in children. New York: Raven, 1990: 381-393