Endocrine Abstracts

Non-hodgkin lymphoma (NHL) is a hematological tumor caused by abnormal lymphoid proliferation. NHL can arise in any part of the body, including central nervous system (CNS). However, hypothalamus involvement is a rare presentation. Here, we report a case of hypothalamic infiltration of NHL Diffuse Large B-cell lymphoma (DLBCL) in a 21 years old male patient with panhypopituitarism and diabetes insipidus. The patient was admitted to the hospital with a history of nausea, vomiting, headache, asthenia, quickly worsening walking impairment and weight loss in two months. He denied neck stiffness and fever. Neurological examination showed global motor slowing, generalized weakness against resistance to head and limbs, no sensitive deficit or focal neurologic sign was recognizable. Hormonal evaluation revealed panhypopituitarism. Non-contrast computed tomography (CT) of the head was performed in the emergency department, showing hydrocephalus and a suprasellar mass. At further imaging a soft tissue mass with a maximum diameter of 14×16 mm on the axial plane, which was located in the infundibulum, optic chiasma and hypothalamus and extending into the third ventricle was also discovered with magnetic resonance imaging (MRI). Ependymoma, metastasis to the hypothalamus, primitive neuroectodermal tumor was speculated for differential diagnosis. Anterior and posterior pituitary was preserved. Lumbar puncture, blood tests, including serology for HIV and other infections, were negative. He was operated and immune histopathological examination of the specimen revealed DLBCL. He was treated with chemotherapy (rituximabe, methotrexate) and cranial radiotherapy. During hospitalization, hypotension, polydispsia, polyuria were observed. Hormonal and clinical evaluation was compatible with central diabetes insipidus and panhypopituitarism. He is still being followed with desmopressin, dexamethasone, levothyroxin and testosterone. The incidence of primary central nervous system lymphoma (PCNSL) has been increasing in recent years, accounting now for 2–6% of all intracranial tumors, although it is considered an uncommon aggressive tumor. Most PCNSL is diffuse large B-cell lymphoma (>95%) whereas T-cell lymphomas are rare. Clinical presentation and imaging findings can vary according to the immune status of the patient. In order to treat the disease optimally, early diagnosis is important. In conclusion, hypothalamic infiltration of NHL on MRI is a rare finding. Diagnosis should be suspected after biochemical analysis and MRI results. Treatment consists of chemotherapy against NHL and hormonal replacement for pituitary dysfunction.