Diagnóstico de neurolinfomatosis como complicación tardía de linfoma no Hodgkin por 18F-FDG PET-CT / Diagnosis of neurolymphomatosis as a late complication of non-Hodgkin lymphoma through 18F-FDG PET-CT

Resumen La neurolinfomatosis (NL) es una condición poco frecuente que se caracteriza por la invasión de células B en los nervios craneales y las raíces nerviosas periféricas y generalmente está vinculada con leucemia o linfoma no Hodking (LNH). En el presente reporte se destacará la importancia de la sospecha diagnóstica en este grupo de pacientes y la importancia de 18F-FDG PET/CT en el diagnóstico diferencial con otras entidades causantes de síntomas similares. Se presenta el caso de una mujer de 63 años con diagnóstico de linfoma difuso de células B grandes, quien, en el tercer ciclo de quimioterapia DA-EPOCH-R, refiere dolor de tipo neuropático en miembro superior derecho, progresivo en severidad y en extensión con compromiso de la extremidad contralateral, convulsiones y parálisis facial periférica.

Abstract Neurolinfomatosis (LN) is a strange condition, defined as Invasion of cranial nerves and peripheral nerve roots by leukemia or lymphoma. Most of the cases are caused by non-Hodgkin's lymphoma of B cells (BHL). The present paper aims to emphasize the importance of suspecting this entity in patients with NHL and neuropathic pain and the role of 18F-FDG PET-CT in the diagnosis. We present the case of a 63-year-old woman diagnosed with diffuse large B-cell lymphoma, who in her third chemotherapy session DA-EPOCH-R of neuropathic pain in the right upper limb, with a poor clinical outcome, due to worsening pain, contralateral limb involvement, seizures and peripheral facial paralysis.

Feline lymphoma in the nervous system: pathological, immunohistochemical, and etiological aspects in 16 cats / Linfoma no sistema nervoso de felinos: aspectos patológicos, imuno-histoquímicos e etiológicos em 16 gatos

The pathological, immunohistochemical (IHC), and etiological features of lymphoma involving the nervous system (NS) in cats were analyzed through a retrospective study (2004-2017) in Rio Grande do Sul State, Brazil. The NS involvement was observed in 16 (12.2%) of 125 felines with lymphoma. Young cats were mainly affected, with a median of 24 months old. Most cases were secondary central NS lymphoma, whereas in three cats, the NS involvement was primary. IHC revealed 14 (87.5%) FeLV-positive, six FIV-positive, and one FeLV/FIV-negative cats. Distribution of feline lymphoma in the NS was 8/16 in the spinal cord, 7/16 in the brain, and 1/16 in the paravertebral nerves and ganglia (neurolymphomatosis). The lymphoma pattern in the spinal cord was exclusively extradural, often focal (6/8), and located in the lumbar (3/6), sacral (1/6), thoracic (1/6), and cervical segments (1/6). Brain neuroanatomical patterns were: leptomeningeal lymphomatosis (4/7), lymphomatous choroiditis (2/7), and intradural lymphoma (1/7). The feline with primary neurolymphomatosis presented a marked thickening of paravertebral nerves and ganglia from the sacral region. B-cell lymphoma (75%) was often diagnosed, and diffuse large B-cell lymphoma (DLBCL) (11/16) was the main subtype. T-cell lymphoma (25%) was less commonly observed and was classified as peripheral T-cell lymphoma (PTCL) (3/16) and T-cell lymphoblastic lymphoma (T-LBL) (1/16).(AU)

Os aspectos patológicos, imuno-histoquímicos (IHQ) e etiológicos do linfoma envolvendo o sistema nervoso de felinos foram analisados através de um estudo retrospectivo (período de 2004-2017) no Estado do Rio Grande do Sul, Brasil. O envolvimento do sistema nervoso foi observado em 16 (12,2%) dos 125 felinos com linfoma desse estudo e afetou principalmente, jovens com idade mediana de 24 meses. A grande maioria dos casos o linfoma era secundário no sistema nervoso central e somente em três gatos o linfoma foi primário do sistema nervoso. Na IHQ, 14 (87,5%) casos foram positivos para FeLV, seis (37,5%) para FIV, e um foi negativo para ambos. A distribuição do linfoma no sistema nervoso foi em 8/16 felinos na medula espinhal, 7/16 no encéfalo e em 1/16 em nervos e gânglios paravertebrais (neurolinfomatose). Na medula espinhal, o padrão do linfoma foi exclusivamente extradural e frequentemente focal (6/8), localizadas nos segmentos lombares (3/6), sacrais (1/6), torácicos (1/6) e cervicais (1/6). No encéfalo, os padrões neuroanatômicos observados foram: linfomatose leptomeningeal (4/7), coroidite linfomatosa (2/7), linfoma intradural (1/7). No felino diagnosticado com neurolinfomatose primária, foi observado acentuado espessamento dos nervos e gânglios paravertebrais da região sacral. Os linfomas de células de células B (75%) foram os mais frequentes e o principal tipo foi o linfoma difuso de grandes células B (11/16). Os linfomas de células T (25%), menos observados, foram classificados como linfomas de células T periférico inespecífico (3/16) e linfoma linfoblástico T (1/16).(AU)

Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

Abstract In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence. This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.