Case Presentation: A 69 year old male patient who at baseline was fully functional, presented with new-onset, progressive left lower extremity (LLE) weakness for 8 days. Patient’s weakness began with difficulty sitting to standing and progressed to inability to climb stairs, requiring a cane and then wheelchair in a span of 5 days. He had associated urinary retention requiring catheterization. Patient denied prior trauma, sensory symptoms or facial and other extremity weakness. Physical exam was significant for 0/5 strength in the left lower extremity with decreased tone, hyporeflexia, external rotation and decreased sensation to temperature and light touch. No Babinski or clonus was elicited and he was unable to ambulate secondary to the weakness. The rest of the neurologic exam was normal.Admission labs normal with Hgb 13.5 g/dl, Wbc 8 k/ul, Plt 162 k/ul, Na 136 mmol/l, K 4.0 mmol/l Cr 0.9 mg/dl. Infectious workup with negative blood cultures. CSF analysis revealed elevated protein and lymphocyte predominant leucocytosis of 17 cu/mm with negative cytology and negative culture VDRL and cryptococcal unremarkable. CT Brain revealed a hypo density in the left frontal region.Further imaging was obtained with MRI Brain and Spine demonstrating two adjacent left frontal lesions (Image 1) and extensive intra-medullary T1-T7 cord enhancement (Image 2). He underwent brain biopsy which revealed High Grade B Cell Lymphoma. Complete workup included a negative Bone Marrow biopsy and normal CT chest/abdomen/pelvis. Treatment with Methotrexate, Vincristine and Dexamethasone was initiated for primary CNS B cell Lymphoma. He slowly regained some movement of his toes and was successfully discharged to rehabilitation.
Discussion: Primary CNS Lymphoma (PCNSL) is a rare condition which represents 4 – 6% of all extra nodal lymphoma. Spinal involvement is rarely reported with an estimated prevalence of less than 1% in patients with PCNSL. 1, 500 patients in the US are diagnosed every year (1). The clinical presentation varies widely with neurologic deficits linked to anatomic involvement, ranging from cranial nerve neuropathies to altered mentation to radiculopathy symptoms such as was present in our patient. The most common risk factor includes immunosuppression however there were no obvious risk factors for the development of PCNSL in our patient.First line treatment involves high dose methotrexate induction therapy with a 5 year survival ranging between 30 – 40% in immunocompetent patients. However HIV related PCNSL patients generally survive 3.6 months after diagnosis.This case had unique characteristic such that our patient presented with acute onset progressive monoparesis with extensive spinal involvement which was not reflected during physical exam given the location of the lesions. Lack of constitutional symptoms and paucity of risk factors also highlights the uniqueness of this patientFinally, the severity of our patient’s weakness as well as the associated urinary retention lead to an early diagnosis which is atypical with PCNSL where the median time to diagnosis is approximately 8 months.
Conclusions: High clinical suspicion on background of History and physical examination coupled with extensive imaging and biopsy are necessary to make a diagnosis of Primary CNS Lymphoma. The rarity of this condition often precludes timely diagnosis and leads to delay in treatment. Favorably in this case, the acuity and severity of the patient’s symptoms prompted him to present early and begin treatment.
