Persons of any age may be affected, but the median age is about 64 years. As is true in most cases of non-Hodgkin's lymphoma, we have no idea. Two studies have reported a relationship with red blood cell transfusions and two studies found no such relationship. This patient had none of those risk factors. HIV infection is not only a risk factor but has therapeutic and prognostic implications as well.
Survival curves are very disappointing, with very high mortality after as little as eight months.
Because we do not understand the etiology of non-Hodgkin's lymphoma, we cannot explain why the incidence has been increasing in the United States since 1957. According to the NCI, non-Hodgkin's lymphomas rank third in increased cancer death rates, preceded by lung cancer in women and prostate cancer in African Americans. Mediastinoscopy is a very reliable approach for mediastinal disease. Laparoscopic biopsy has recently been demonstrated to be effective and reliable in abdominal disease. If the clinical condition of the patient is such that surgical biopsy is contraindicated, or if the disease site is difficult to reach, the diagnostic procedure of choice may be a needle biopsy, preferably a core-needle biopsy.