Paralyzed by a rare cause: an unusual case of metastatic diffuse large B cell lymphoma of the intramedullary spinal cord.

Dear Editor, Diffuse large B cell lymphoma (DLBCL) has been known to occur in the central nervous system (CNS) as primary CNS lymphoma [1] or as secondary involvement from a systemic disease. DLBCL has been rarely reported to present as intramedullary spinal cord metastasis (ISCM) [2]. Our patient, Ms. A, was a 74-year-old female diagnosed with DLBCL 1 year prior to her presentation due to a pelvic mass involving the left sacroiliac joint. She completed six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone followed by radiation to the mass. She did well for about 3 months. Three months later, she developed progressive lower extremity weakness. She was seen a few months later in our institution. She had urinary and bowel incontinence on admission. Exam on admission revealed symmetric sensory loss extending from bilateral lower extremities and paralysis. An MRI was contraindicated due to the presence of an incompatible cardiac pacemaker. Hence, a CT myelogram was performed which revealed expansion of the upper thoracic cord at the level of fourth and fifth thoracic vertebrae, suggestive of an intramedullary lesion (Fig. 1a, b). Bone marrow biopsy was normal. LP showed no evidence of malignancy or of a clonal population. PET/CT showed increased metabolic activity along the spinal cord canal involving the third, fourth, and fifth thoracic vertebral levels without osseous deformity (Fig. 1c, d), strongly suggestive of recurrent disease. PET/CT scan did not show disease elsewhere. Due to the high possibility for a lymphomatous process, she was started on steroids and she was evaluated by neurosurgery service. She underwent biopsy and subtotal resection of the intramedullary tumor with laminectomies of T3 through T5 vertebra. Pathology of the operative specimen revealed diffuse large B cell lymphoma, consistent with a germinal center origin. The surgical intervention, however, did not result in any clinical improvement. Since she was not a candidate for systemic chemotherapy, radiation therapy was initiated, but the treatment remained incomplete due to development of acute respiratory failure from healthcareassociated pneumonia. Intrathecal chemotherapy was also discussed, but she did not receive it since her condition continued to worsen necessitating ICU admission. At this point, given the paucity of clinical options and grim prognosis, the family decided to make her comfort care. The intramedullary spinal cord is a rare location for tumor metastasis, most commonly associated with lung and breast cancer [3, 4]. Intramedullary spinal cord metastasis from diffuse large B cell lymphoma has been very rarely reported in the literature. A recent case series from Mayo clinic [2] detailed the presentation of seven patients with non-Hodgkin’s lymphoma and ISCM over the course of 14 years. Three of these patients had pathology-proven DLBCL. Although the most common modality used for detection is the MRI, if this is contraindicated as in our case, a combination of CT myelography and PET can lead to localization of the metastatic lesion. Various therapeutic approaches have been made to treat the ISCM, but the results have been poor. However, as suggested by existing A. Rao Department of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA