|
June 2009 Case of the Month
Compiled by: Malcolm Shupeck, M.D., F.A.C.S.
History: Fever, splenomegaly, maculopapular rash, jaundice
Exam:MRI brain pre- and post-contrast T1 without fat suppression, axial flair coronal and axial T2, 3-D SENSE and diffusion-weighted images.
Images & Findings:
Figure 1: Axial T2 demonstrating occipital necrosis and volume loss.
Figure 2: T1 coronal, with contrast demonstrating mild residual enhancement.
Figure 3: T1 axial, with contrast demonstrating occipital necrosis and volume loss with absence of the lesional enhancement seen in the early phase of the illness.
Figure 4: 3-D SENSE, with arrow demonstrating occipital volume loss and necrosis.
Figure 5: Diffusion restriction may be seen in the early phase of disease. Late-phase- signal absence due to progression to necrosis seen at arrow point.
Figure 6: T1 non-contrast with arrow on necrotic occipital lesion.
Figure 1
|
Figure 2
 |
Figure 3
|
Figure 4
 |
Figure 5
 |
Figure 6
 |
Diagnosis:Hemangiophagocytic lymphohistiocytosis
Discussion:
Hemangiophagocytic lymphohistiocytosis is a rare condition of young children, usually presenting before one year of age. Two forms exist: 1) A primary genetic form with an autosomal recessive inheritance, and 2) A secondary form presenting in the setting of infection, malignancy, and prolonged immunosuppression.
Clinical manifestations include coagulopathy, infection, splenomegaly, and rash, which may progress to seizures, coma, opisthotonus, and, ultimately, cardiac and respiratory abnormalities and death. Patients may present with retinal and cerebral hemorrhages, some of which have been diagnosed as possible child abuse.
Pathophysiology includes an aggressive proliferation of macrophages and lymphocytes that phagocytize red cells, white cells, and platelets. Central nervous system involvement is reported in 73% of cases. An initially leptomeningal process progresses to perivascular infiltration and astrocytic proliferation, primarily affecting the white matter with focal demyelination. Extra-axial subarachnoid and parenchymal hemorrhage may develop.
The most commonly seen MRI findings are parenchymal volume loss with focal necrosis and white-matter abnormalities. Diffuse perivascular and leptomeningeal enhancement related to the degree of histiocyte and lymphocytic infiltration is common in the earlier stage of disease, with an appearance similar to leukemic infiltration.
Multiple enhancing lesions with T2 prolongation have been observed, as well as ring- enhancing mass lesions with appearance similar to cerebral abscesses. Diffusion-weighted images may demonstrate diffusion restriction, which may aid in differentiation from toxoplasma and tuberculosis (in which diffusion is often normal). Restricted diffusion may be seen in pyogenic and fungal abscesses.
Hemangophagocytic lymphohistiocytosis may be an additional differential consideration in young children with a history of immunosuppression or genetic predisposition who present with an MRI appearance of leukemic infiltration in the disease’s initial phase, or brain abscess in its more advanced forms. The entity may be included in the differential diagnosis of child abuse in the appropriate clinical setting.
References:
- Forbes KPN, Collie D, Parker A. “CNS Involvement of Virus-Associated Hemaphagocytic Syndrome: MR Imaging Appearance.” AJNR 2000; 21:1248-1250.
- Ozgen B, Karil-Oguz K, Sarikaya B, Tavil B, Gurgey A. “Diffusion-Weighted Cranial MR Imaging Findings in a Patient with Hemophagocytic Syndrome.” AJNR 2006; 27:1312-1314.
- Haddad E, Sulis ML, Jabado N, Blanche S, Fischer A,Tardieu M. “Frequency and Severity of Central Nervous System Lesions in Hemophagocytic Lymphohistiocytosis.” Blood 1997; 89(3):794-800.
- Chung TW. “CNS Involvement in Hemophagocytic Lymphohistiocytosis: MR Findings.” Korean Journal of Radiology 2007; 8(1):78-81.
- Rooms L, Fitzgerald N, McClain KL. “Hemangiophagocytic Lymphyohistiocytosis Masquerading as Child Abuse: Presentation of Three Cases and Review of Central Nervous System Findings in Hemophagocytic Lymphohistiocytosis.” Pediatrics 2003; Vol.111, No.5:pe636-e640.
|
