RESUMO
Head and neck paragangliomas are rare neuroendocrine tumors expressing somatostatin receptors on their cell surface, particularly subtype 2. Due to this distinctive feature, images can be obtained in Nuclear Medicine using synthetic analogues of somatostatin, mainly octreotide, which allow selective display by planar scintigraphy, SPECT-CT or PET-CT imaging after radiolabeling with (111)In or (68)Ga. Three cases have been selected and presented from a series of patients that illustrate the utility of SPECT-CT studies with (111)In-octreotide in the diagnosis and monitoring of this type of tumor. These are characterization at initial diagnosis, staging, and detection of local recurrence or metastasis, with added value with respect to anatomical images (nuclear magnetic resonance, computed axial tomography, angiography), for example in the differentiation between functional tissue or scar in patients who had previously undergone surgery.
Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Paraganglioma Extrassuprarrenal/diagnóstico por imagem , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Tumor do Corpo Carotídeo/diagnóstico por imagem , Tumor do Corpo Carotídeo/cirurgia , Cicatriz/diagnóstico , Diagnóstico Diferencial , Feminino , Tumor de Glomo Timpânico/química , Tumor de Glomo Timpânico/diagnóstico por imagem , Tumor de Glomo Timpânico/cirurgia , Neoplasias de Cabeça e Pescoço/química , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Radioisótopos de Índio , Metástase Linfática/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Neoplasia Residual , Octreotida/análogos & derivados , Paraganglioma Extrassuprarrenal/química , Paraganglioma Extrassuprarrenal/secundário , Paraganglioma Extrassuprarrenal/cirurgia , Complicações Pós-Operatórias/diagnóstico , Compostos Radiofarmacêuticos , Receptores de Somatostatina/análiseRESUMO
Jugulo-tympanic paraganglioma is the most commonly recognized neoplasia involving the middle ear, arising from chemopressure receptors. Clinical presentation is variable, with otalgia, dizziness and cranial nerve palsies. This tumor usually occurs in middle aged women and its presentation may be familiar, sporadic, bilateral or multicentric. In the present case the patients presented with otalgia and bradyacusia diagnosed with chronic otitis. A bleeding polypoid lesion in middle ear was seen during surgery. Frozen section of intraoperative specimen showed monomorphic cells organized into nests, without aspects of malignancy, into a highly vascularized stroma. Immunohistochemical analysis revealed two type of cells: chief cells immunostained for chromogranin and synaptophysin and sustentacular cells immunostained for S-100 protein. Clinical presentation of jugulotympanic paraganglioma, when it isn't associated with evidence of hormone secretion, is referred prevalently to bradyacusia, dizziness, and cranial nerve palsies. In event of localized disease, paragangliomas often can be treated by surgical excision, but some cases need radiation therapy.
