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Neuroradiology Case of the Week

Case 148

Alisa Johnson, Loris Cedeno, MD and PL Westesson MD, DDS, PhD

Clinical Presentation: The patient is a 47-year-old male who is presents with a history of diffuse lymphadenopathy and proptosis. The patient is a follow up case of follicular lymphoma. He complains of back pain and facial swelling.

Radiological Findings:

CT: Proptosis is seen on both sides, left more than right.  There are homogeneous density opacities seen in the extraconal compartment of both the globes.  There is enlargement of the tonsils and adenoids causing indentation of the oropharyneal lucency which appears narrowed.  Multiple soft tissue thicken with homogeneous nature is seen involving the facial soft tissue on both sides.

MRI: There is partial collapse of L4 vertebral body.  The vertebra is bright on T1 and of low signal intensity on T2. Following Gadolinium administration, there is enhancement of the vertebra and the associated large perivertebral mass that also has an epidural component that markedly compromises the canal diameter and compressing the thecal sac. Enhancing soft tissue mass is also seen in the neural foramen. Streaky enhancement is seen in the paraspinal soft tissues and psoas muscle indicating tumor infiltration. In the prevertebral region there is a large enhancing mass that encases and displaces the aorta. Enhancing mass is also seen extending into the presacral space and displacing the rectum and sigmoid anteriorly. Perinephric space enhancement indicating tumor infiltration is seen bilaterally. This extends around the adrenal glands. There is bilateral hydronephrosis, right more than left.

Body CT Kidneys and Collecting Systems: Asymmetric perfusion.  There is severe right hydronephrosis secondary to massive lymphadenopathy. There is moderate left hydronephrosis. Also secondary to massive lymphadenopathy. Vessels: The IVC is displaced anteriorly due to lymphadenopathy. The lymph nodes encase the aorta, renal arteries and compress the renal veins.

Clinical Discussion: Follicular lymphoma is the most common of the indolent non-Hodgkin's lymphomas and comprises approximately 20% of all non-Hodgkin's lymphomas. Estimates indicate that more than 15,000 to 20,000 cases of follicular lymphoma are diagnosed per year in the United States. Median age at diagnosis is 60-65 years. The incidence of follicular lymphomas increases with age with a slight female predominance. Follicular lymphoma is defined as a lymphoma of follicle center B-cells, which has a partially follicular pattern. Follicular lymphomas typically have a chromosomal abnormality referred to as (t14:18), which is associated with the bcl-2 oncogene [1,2].
     Follicular lymphoma commonly presents with painless peripheral lymphadenopathy which waxes and wanes. Other symptoms may also be present such as fatigue, fever, and weight loss. Extensive lymphadenopathy can also cause symptoms such as gastrointestinal obstruction or peripheral nerve compression. Often patients present with multiple sites of nodal disease with the involvement of the bone marrow, liver and spleen. Osseous lymphoma composes 3-4% of all bone tumors [3]. Despite the fact that most follicular lymphomas are advanced at the time of diagnosis, the median survival of patients with follicular lymphomas is approximately 10 years. On physical exam the enlarged lymph nodes are non-tender, firm, and rubbery in consistency and splenomegaly is appreciated in half of the patients at presentation. Imaging is done both to assist with diagnosis and to assess the extent of the lymphoma. However, biopsy is essential to establish a diagnosis of lymphoma. Despite the indolent clinical course of follicular lymphomas it is not usually curable. Virtually all patients with follicular lymphoma eventually die of this disease [4].

Neuroimaging Discussion: Osseous manifestations of non-Hodgkin's lymphoma (NHL).
     When lymphoma involves bone it indicates stage IV disease and is found at presentation in 20-40% of patients with NHL. MRI is very sensitive to bone marrow involvement and appears as a low intensity signal on T1WI. On short tau inversion recovery and T2WI it appears as high signal intensity and shows enhancement with Gadolinium. NHL can have primary or secondary cortical bone involvement. In primary bony lesions NHL will demonstrates an osteolytic pattern of bone destruction in over 75% of patients and often affects the appendicular skeleton such as the femur, humerus, or tibia. Secondary bone involvement tends to involve the spine as in the patient presented above. If you see an “ivory vertebra” and a paravertebral mass on plain film in a young patient you should suspect lymphoma [5]. The “ivory vertebra” sign describes a uniformly white vertebra with no abnormal contours or adjacent disks on plain film.

References:

1. The Non-Hodgkin's Lymphoma Classification Project. A clinical evaluation of the International Lymphoma Study Group classification of non-Hodgkin's lymphoma. Blood 1997; 89:3909-3918.
2. The Non-Hodgkin's Lymphoma Pathologic Classification Project. National Cancer Institute sponsored study of classifications of non-Hodgkin's lymphomas: summary and description of a working formulation for clinical usage. Cancer 1982; 49:2112.
3. Ross J, Brant-Zawadzki M, Chen M, Moore K, Salzman K. Diagnostic Imaging: Spine, 1st ed. Amirsys Inc: Altona, 2004.
4. Freytes CO. Lymphoma, follicular. http://www.emedicine.com/med/topic1362.htm, July 2002
5. Hricak BR. Oncologic Imaging, 2nd ed. W.B. Saunders Company: Philadelphia, 2002.