We present the case of a 59-year-old gentleman with history of hypertension, dyslipidemia, and ankylosing spondylitis who presented with a 3-week history of left chin numbness. The sole significant physical exam finding was numbness in left V3 region that extended 2.5 cm laterally from midline of chin.  Additional review of systems was negative. The patient was taking adalimumab for ankylosing spondylitis and medication was discontinued.  MRI with and without contrast revealed lesions of the diploic space and an enhancing scalp lesion in the parietal region. Initial scalp biopsy showed atypical lymphocytic infiltrate. Full-body CT/PET scan showed nodal, skin, and marrow-based hypermetabolism. On the day of the marrow biopsy, no abnormal circulating populations were seen on peripheral smear and pathology showed normocellular bone marrow with large atypical lymphoid cells. The diagnosis of T-cell-rich diffuse large B-cell lymphoma was made 53 days following presentation. Just prior to initiating chemotherapy, patient developed generalized fatigue. The mental neuropathy has persisted following multiple cycles of chemotherapy.

NCS has been reported to herald underlying malignancy¹.  In addition, ankylosing spondylitis has been associated with increased incidence of lymphomas².  The concern for malignancy should be further heightened in patients with mental neuropathy and ankylosing spondylitis thus requiring a complete and expeditious evaluation.  

References:

1. 1. Galan GilS, Penarrocha. Malignant mental nerve neuropathy. Med Oral Patol Oral Cir Bucal. 2008;13(10):E616–21.
2. 2. Deng, C. et al. Risk of malignancy in ankylosing spondylitis: a systematic review and meta-analysis. Sci. Rep.6, 32063; doi: 10.1038/srep32063 (2016).