RESUMO
Schwannomas are benign soft-tissue tumors that arise from peripheral nerve sheaths throughout the body and are commonly encountered in patients with neurofibromatosis Type 2. The vast majority of schwannomas are benign, with rare cases of malignant transformation reported. In this pictorial review, we discuss the magnetic resonance imaging (MRI) appearance of schwannomas by demonstrating a collection of tumors from different parts of the body that exhibit similar MRI characteristics. We review strategies to distinguish schwannomas from malignant soft-tissue tumors while exploring the anatomic and histologic origins of these tumors to discuss how this correlates with their imaging findings. Familiarity with the MRI appearance of schwannomas can help aid in the differential diagnosis of soft-tissue masses, especially in unexpected locations.
RESUMO
Lymphoma of the peripheral nerve, particularly of the T-cell variety, is an extremely rare subtype of extra nodal lymphoma that has a variable response to current therapeutic regimens. Here, we present a patient with natural killer (NK)/T-cell lymphoma in remission who presented with a two-month history of right forearm swelling and paresthesia in the ulnar nerve distribution. Magnetic resonance imaging (MRI) showed an ulnar nerve mass identified as a nerve sheath tumor. Frozen section and postresection biopsies showed an Epstein-Barr virus-positive NK/T-cell lymphoma, nasal type. Consequently, the patient received chemotherapy following resection. Four months later, the patient developed a proximal leg mass, which was diagnosed as tibial nerve lymphoma. The patient was then treated with chemotherapy and follow-up was done by positron emission tomography-computed tomography (PET-CT). In conclusion, lymphoma should be considered in the differential diagnosis of a peripheral nerve mass. MRI is a useful imaging tool together with PET-CT, which plays a beneficial role in the follow-up of these patients on therapy as well as diagnosis of new lesions.
