Non-Hodgkin lymphoma diagnosis

Diagnosis
If non-Hodgkin's lymphoma is suspected, the doctor asks about the person's medical history and performs a physical exam. The exam includes feeling to see if the lymph nodes in the neck, underarm, or groin are enlarged. In addition to checking general signs of health, the doctor may perform blood tests.

The doctor may also order tests that produce pictures of the inside of the body. These may include:
 * X-rays: Pictures of areas inside the body created by high-energy radiation.
 * CT scan (computed tomography scan, also known as a "CAT scan"): A series of detailed pictures of areas inside the body. The pictures are created by a computer linked to an x-ray machine.
 * PET scan (positron emission tomography scan): This is an imaging test that detects uptake of a radioactive tracer by the tumor. More often, the PET scan can be combined with the CT scan.
 * MRI (magnetic resonance imaging): Detailed pictures of areas inside the body produced with a powerful magnet linked to a computer.

Less commonly used

 * Lymphangiogram: Pictures of the lymphatic system taken with x-rays after a special dye is injected to outline the lymph nodes and vessels. This test is not used as often because of the adoption of CT scan and the PET scan technologies.
 * Gallium scan: Gallium is a rare metal that behaves in the body in a fashion similar to iron, so that it concentrates in areas of inflammation or rapid cell-division, and hence is useful for imaging the entire lymphatic system for staging of lymphoma once the presence of the disease has been confirmed. PET scans have supplanted gallium scans for evaluation and follow up of NHL.

Biopsy
A biopsy is needed to make a diagnosis. A surgeon removes a sample of tissue, which a pathologist can examine under a microscope to check for cancer cells. A biopsy for non-Hodgkin's lymphoma is usually taken from lymph nodes that are enlarged, but other tissues may be sampled as well. Biopsies in internal lymph nodes can also taken as needle biopsies under the guidance of CT scans. Rarely, an operation called a laparotomy may be performed. During this operation, a surgeon cuts into the abdomen and removes samples of tissue to be checked under a microscope.