Hypothalamic relapse of a cardiac large B-cell lymphoma presenting with memory loss, confabulation, alexia-agraphia, apathy, hypersomnia, appetite disturbances and diabetes insipidus.

A 37-year-old Hispanic man with a right atrial intracardiac mass diagnosed as diffuse large B-cell lymphoma (DLBCL) was successfully treated with surgery and chemotherapy. During 4 years, several total-body positron emission tomography and MRI scans showed no extracardiac lymphoma. On year 5 after the cardiac surgery, patient presented with sleepiness, hyperphagia, memory loss, confabulation, dementia and diabetes insipidus. Brain MRI showed a single hypothalamic recurrence of the original lymphoma that responded to high-dose methotrexate treatment. Correction of diabetes insipidus improved alertness but amnesia and cognitive deficits persisted, including incapacity to read and write. This case illustrates two unusual locations of DLBCL: primary cardiac lymphoma and hypothalamus. We emphasise the importance of third ventricle tumours as causing amnesia, confabulation, behavioural changes, alexia-agraphia, endocrine disorders and alterations of the circadian rhythm of wakefulness-sleep secondary to lesions of specific hypothalamic nuclei and disruption of hypothalamic-thalamic circuits.

Complement activation: an atypical presentation of an atypical syndrome.

A 42-year-old Hispanic female and long-distance runner was seen for evaluation of fatigue. Her physical examination showed petechiae and ecchymoses in upper extremities, abdominal distension and bilateral ankle oedema. Laboratory workup revealed anaemia, thrombocytopenia, hypoalbuminemia and proteinuria of 1.4 g/24 hours. No schistocytes were found on peripheral blood smear. CT of her abdomen revealed diffuse small lymphadenopathy and hepatomegaly. Bone marrow biopsy demonstrated normal trilineage hematopoiesis with no hemophagocytosis. The patient was started on oral prednisone with no improvement and was subsequently admitted to the hospital for pulsed steroids, intravenous immunoglobulin and rituximab. Her proteinuria became nephrotic range, and a renal biopsy revealed features of thrombotic microangiopathy limited to the glomerular capillaries. ADAMTS13 was low which is >10% of normal, and a diagnosis of atypical haemolytic-uraemic syndrome (aHUS) was made. Eculizumab was started with prompt response. Whole exome sequencing demonstrated mutation in SPTA1, which has been associated with red blood cell membrane diseases but has not been described in patients with aHUS.

Atypical NK-cell proliferation of the gastrointestinal tract in a patient with antigliadin antibodies but not celiac disease.

We describe a unique case of atypical natural killer (NK)-cell proliferation likely related to gluten sensitivity, mimicking NK-cell lymphoma. The patient, a 32-year-old man, has had persistent multiple erythematous bull-eye lesions in the stomach, small bowel, and large bowel for 3 years. Histologically, the lesions were well circumscribed and relatively superficial, composed of atypical medium-sized to large-sized lymphocytes with slightly irregular nuclear contours, a dispersed chromatin pattern, and clear cytoplasm. Immunohistochemistry and flow cytometry showed that the cells were NK cells expressing CD56 (aberrantly bright), T-cell intracellular antigen (TIA)-1, cytoplasmic CD3, and CD94, but not surface CD3, with bright aberrant expression of CD7 and a lack of other NK cell-associated markers. Polymerase chain reaction for rearrangement of the T-cell receptor-gamma chain gene showed no evidence of a clonal T-cell population, and in situ hybridization for Epstein-Barr virus encoded RNA was negative. There was no evidence of the involvement of peripheral blood or bone marrow. Although a diagnosis of extranodal NK/T-cell lymphoma was considered because of the atypical morphology and immunophenotypic aberrancy, no chemotherapy was given because of the relatively superficial nature of the infiltrates, lack of significant symptoms, and negativity for Epstein-Barr virus. Two years after initial presentation, the patient was found to have high titers of antigliadin antibodies with no other evidence of celiac disease. After instituting a gluten-free diet, many of the lesions regressed, suggesting that this atypical NK-cell proliferation may be driven by an anomalous immune response. Awareness of this case may prevent pathologists from misdiagnosing similar lesions as NK/T-cell lymphomas. It is as yet unknown whether this process occurs more commonly in patients with gluten sensitivity, or in other settings, and the pathogenesis is as yet undetermined.