What are primary central nervous system lymphomas?

Related conditions:
Immunodeficient states including acquired immunodeficiency syndrome
(AIDS), organ transplantation, prolonged immunosuppressive therapy,
Wiskott-Aldrich syndrome, and Sjögren syndrome

Definition:
Primary central nervous system lymphoma is a malignant tumor of the brain,
spinal cord, or meninges; it can occur in both normal and immunocompromised
patients.

Risk factors: The main risk factor for primary central nervous system
lymphoma is immunosuppression, including acquired immunodeficiency
syndrome (AIDS), ataxia-telangiectasia, Wiskott-Aldrich
syndrome, and solid organ transplantation.

Etiology and the disease process: Primary central nervous system
lymphoma, if associated with AIDS, can manifest as poorly differentiated brain
masses associated with hemorrhage and necrosis, composed of B cells (B
lymphocytes), although T-cell lymphomas can also occur. It is thought that the
dysfunction of suppressor T cells in AIDS patients leads to this B-cell
lymphocytic cancer. In patients with normal immune systems, the tumor is usually
more focal and well-circumscribed and is usually not associated with hemorrhage
and necrosis.

Incidence: Primary central nervous system lymphoma makes up 1 to 2
percent of all intracranial neoplasms and 1 percent of all primary non-Hodgkin
lymphomas. It occurs in 6 percent to 30 percent of patients with AIDS. The most
common type to affect the brain is diffuse histiocytic lymphoma, also known as
reticulum cell sarcoma. Primary central nervous system lymphoma is the most common
brain
tumor due to the human immunodeficiency virus.

Symptoms: Although primary central nervous system lymphoma can occur
in all age groups, the average age at which it is diagnosed in normal adults is
age sixty, but in immunocompromised patients it is found at the much younger
average age of thirty-three. Symptoms vary depending on lesion site and include
headaches, seizures, focal neurologic impairment, fatigue, vertigo, language
deficits, ataxia, and behavioral abnormalities.

Screening and diagnosis: Brain magnetic resonance imaging (MRI)
findings often include periventricular and deep gray matter lesions with masses
usually less than 2 centimeters in AIDS patients and greater than 2 centimeters in
non-AIDS patients. Diagnosis requires histopathological confirmation.

Treatment and therapy: Whole brain irradiation was the standard
therapy for primary central nervous system lymphomas, but this has been mostly
replaced by combination chemotherapy and radiation therapy. Chemotherapeutic
medications include dexamethasone, methotrexate, and cytarabine.

Prognosis, prevention, and outcomes: The prognosis is poor, with a
median survival of 13.5 months after diagnosis.

Basmaci, Mehmet, et al. "Management of
Primary Diffuse Large B-Cell Lymphoma of the Central Nervous System:
Clinical Study." Journal of Neurological Sciences 30.2
(2013): 469–76. Print.

Hayat, M. A., ed. Tumors of the
Central Nervous System. Dordrecht: Springer, 2012.
Print.

Norden, Andrew D., David A. Reardon, and
Patrick Y. C. Wen, eds. Primary Central Nervous System Tumors:
Pathogenesis and Therapy. New York: Humana, 2011.
Print.

Prica, Anca, et al. "Combined Modality
Therapy versus Chemotherapy Alone as an Induction Regimen for Primary
Central Nervous System Lymphoma: A Decision Analysis." British
Journal of Haematology 158.5 (2012): 600–07. Print.

Shibamoto, Y., et al. "Analysis of
Radiotherapy in 1,054 Patients with Primary Central Nervous System Lymphoma
Treated from 1984 to 2009." Clinical Oncology 26.10 (2014):
653–60. Print.