Peripheral T-cell lymphomas (PTCLs) are rare and heterogeneous haematological malignancies that can rarely develop first in the peripheral nervous system, or more commonly, invade nerves from more usual primary locations. Patients with PTCLs usually respond poorly to treatment and have a poor clinical outcome.
We report a patient with multiple skin lesions, multifocal mononeuropathies and constitutional symptoms all suggestive of a lymphoproliferative disorder, in whom repeat skin biopsies and clonality studies failed to achieve a diagnosis. Neurophysiological studies confirmed severe post-ganglionic lesions in the lower limbs including the sciatic, femoral, obturator, tibial and sural territories. Based on this neurotropic presentation we undertook a sural nerve biopsy, despite the clinical and neurophysiological presence of a nerve lesion more proximal to the biopsy site, and this allowed us to establish a final diagnosis of PTCL. The patient was treated successfully with chemotherapy and an autologous stem cell transplant.
In our case PET imaging and MR neurography provided radiological evidence of widespread lesions in the subcutaneous and nerve tissues, and there is emerging evidence for the importance of PET imaging in the diagnostic work-up of PTCLs. Furthermore, a post-treatment PET scan confirmed the complete metabolic remission, highlighting its usefulness as a surveillance tool.