Abstracts

Rationale: Lamotrigine is a newer and now widely used FDA approved anticonvulsant for treatment of partial seizures with secondary generalization. Well known and recognized adverse effects of lamotrigine include rash and leukopenia. Pseudolymphoma syndrome may be associated with traditional anticonvulsants including phenytoin, valproic acid, phenobarbitol, and carbamazepine. The syndrome includes lymphadenopathy, fever, rash, and hepatitis. We report two patients who developed atypical pseudolymphoma after starting lamotrigine. We present their cases and review the literature on anti-convulsant induced pseudolymphoma. Methods: Patient 1. A 40 y.o. female had a history of generalized seizure disorder, hemi-plegic migraine, and depression with incomplete seizure control on carbamazepine. Lamotrigine adjunctive therapy was initiated with significant improvement of seizure control. Three years later computed tomography of the neck demonstrated findings believed consistent with cervical lymphoma. There was no associated fever, rash, nor hepatitis. Following clinical and laboratory evaluation by neurology and hematology/ oncology, a biopsy was performed and demonstrated lymphoid hyperplasia, with no evidence of B- or T-cell lymphoma. Lamotrigine was discontinued. Her other medications were not changed. Repeat laryngoscopy was performed 4 weeks later and confirmed complete resolution of the hyperplastic adenoid tissue. Patient 2. A 68 y.o.male had a history of localization related seizure disorder secondary to a left middle cerebral artery aneurysm rupture. He was initially treated with phenytoin and subsequently transitioned to lamotrigine for long-term anti-convulsant therapy. Two months later he developed diffuse, predominantly upper body subcutaneous nodules which were not considered to be a lamotrigine associated rash. Following evaluation by hematology/oncology a biopsy was performed and demonstrated lymphoid infiltrate, suspicious for T-cell lymphoma. Lamotrigine was discontinued at that time and there was complete resolution of all skin lesions within 3 weeks. Results: Two patients developed lymphoid hyperplasia after initiation of lamotrigine adjunctive therapy. Neither patient had fever, rash, nor hepatitis as is more commonly seen in the syndrome of anticonvulsant related pseudolymphoma and thus both were referred to hematology oncology for evaluation and subsequently had tissue biopsy. Both patients showed complete resolution of the lymphoid hyperplasia with discontinuation of lamotrigine. Conclusions: 1. Pseudolymphoma can develop in patients treated with lamotrigine. 2. Both of the cases we report lacked fever, rash, and hepatitis as is seen with traditional anticonvulsant related pseudolymphoma syndrome. 3. The time course of development of lymphoid hyperplasia after initiation of lamotrigine is unknown. 4. Lymphoid hyperplasia was reversible with discontinuation of lamotrigine within a relatively short period of time. 5. Early recognition of lamotrigine associated lymphoid hyperplasia may help avoid unnecessary invasive evaluations including biopsy.