[Neurolymphomatosis: diagnosis of extension and assessment of response to treatment with PET-CT]. / Neurolinfomatosis: diagnóstico de extensión y valoración de la respuesta al tratamiento mediante PET-TAC.

Neurolymphomatosis is a rare neurological manifestation of non-Hodgkin's lymphoma (NHL) and it may be its first and sole manifestation. Diagnosis is often difficult and nerve biopsy is generally required. However, this it is not always possible to perform or is not conclusive. We present the case of a 66-year-old woman diagnosed with giant B-cell NHL. After 6 cycles of chemotherapy, imaging and molecular biology techniques showed complete remission. At four months after treatment, the patient complained of low back pain of radicular distribution. CT and MRI imaging showed signs of lymphoproliferative activity of L5 and also lesions to thoracic nerve roots. A PET-CT was requested in order to complete the diagnosis and plan the treatment. Imaging confirmed the presence of tumor recurrence with neurolymphomatosis and also indicated lesions on the chest and abdominal level. Thus, it was decided to start a new line of chemotherapy, without performing the histological study through biopsy. This case illustrates the important role played by PET-CT imaging in neurolymphomatosis diagnosis. This technique can help the patient avoid more aggressive procedures, such as a biopsy, and can also be useful in the follow-up and assessment of the treatment response to NHL-diagnosed patients.