Severe hyponatraemia in a patient with secondary central nervous system lymphoma

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Hareesh Joshi,Thiagarajan A, Prachi P,Oyibo SO and Sagi SV

Peterborough City Hospital, UK

: Endocrinol Diabetes Res

Abstract

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Introduction: Central nervous system (CNS) lymphoma is a rare complication of non- Hodgkin’s lymphoma. It can be primary malignant growth of lymph tissue within the brain and spinal cord or secondary spread from other parts of the body. Hyponatraemia is the commonest electrolyte disorder and has a large differential diagnosis. We present an interesting case exhibiting both conditions. Case: A 76-years-old female presented with drowsiness and unresponsiveness. Four weeks ago she had sudden onset double vision in left eye, headache and numbness of the left side of her face. She had a past medical history of non-Hodgkin’s lymphoma treated with chemotherapy and radiotherapy. Examination revealed 5th and 6th cranial nerve palsies. Respiratory and cardiovascular systems were unremarkable and she was not dehydrated. Laboratory tests revealed severe hyponatraemia (serum sodium = 116 mmol/l), hypo-osmolality (serum Osmolality =232 mOsm/kg ) and raised urine osmolality (546 mOsm/kg), suggestive of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH). Her MRI scan showed abnormal T2 signal changes but no meningeal disease. Cerebrospinal fluid sampling revealed predominant lymphocytosis and raised protein (2.70g/L). Cytology revealed atypical lymphoid cells in keeping with lymphoma. Despite fluid restriction and treatment with Demeclocycline, serum sodium levels remained stagnant. This later responded to a single dose of Tolvaptan. Further follow-up was with the Haematologist. Conclusion: Secondary CNS lymphoma complicated by SIADH is a rare presentation. This patient’s hyponatraemia was refractory to fist-line treatment and responded only after use of Tolvaptan. SIADH secondary to malignant processes can be resistant to first-line treatment.

Biography

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H Joshi is a Registrar in Department Endocrinology at Peterborough City Hospital UK A Thiagarajan is a Registrar in Department of Nephrology at Peterborough City Hospital UK P Prachi is a Registrar in Department of Endocrinology at Peterborough City Hospital UK S Sagi is a Consultant in Diabetes and Endocrinology at Peterborough City Hospital UK S Oyibo is a Consultant in Diabetes and Endocrinology at Peterborough City Hopsital UK

E-mail: hareesh.joshi@nhs.net