RESUMO
Introduction Schwannoma of the olfactory groove is an extremely rare tumor that can share a differential diagnosis with meningioma or neuroblastoma. Objectives The authors present a case of giant schwannoma involving the anterior cranial fossa and ethmoid sinuses. Case Report The patient presented with a 30-month history of left nasal obstruction, anosmia, and sporadic ipsilateral bleeding. Computed tomography of the paranasal sinuses revealed expansive lesion on the left nasal cavity extending to nasopharynx up to ethmoid and sphenoid sinuses bilaterally with intraorbital and parasellar extension to the skull base. Magnetic resonance imaging scan confirmed the expansive tumor without dural penetration. Biopsy revealed no evidence of malignancy and probable neural cell. Bifrontal craniotomy was performed combined with lateral rhinotomy (Weber-Ferguson approach), and the lesion was totally removed. The tumor measured 8.0 4.3 3.7 cm and microscopically appeared as a schwannoma composed of interwoven bundles of elongated cells (Antoni A regions)mixed with less cellular regions (Antoni B). Immunohistochemical study stained intensively for vimentin and S-100. Conclusion Schwannomas of the olfactory groove are extremely rare, and the findings of origin of this tumor is still uncertain but recent studies point most probably to the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. .
Assuntos
Animais , Feminino , Masculino , Camundongos , Permeabilidade da Membrana Celular/fisiologia , Células Ciliadas Auditivas/fisiologia , Canais Iônicos/fisiologia , Mecanotransdução Celular/fisiologia , Animais Recém-Nascidos , Caderinas/genética , Permeabilidade da Membrana Celular/genética , Quelantes/farmacologia , Sulfato de Di-Hidroestreptomicina/farmacologia , Embrião de Mamíferos , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Células Ciliadas Auditivas/citologia , Células Ciliadas Auditivas/efeitos dos fármacos , Técnicas In Vitro , Canais Iônicos/efeitos dos fármacos , Camundongos Transgênicos , Mecanotransdução Celular/efeitos dos fármacos , Mecanotransdução Celular/genética , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/genética , Miosinas/genética , Órgão Espiral/citologia , Precursores de Proteínas/genéticaRESUMO
The potassium channels are ubiquitous multisubunit membrane proteins, and potassium-dependent alterations in the membrane potential play an important role in the proliferation of many types of cells. This study analyzed the mutation, allelic loss and expression patterns of the KCNRG gene in 77 HCCs in order to determine if the KCNRG gene, which encodes the potassium channel regulating protein, is involved in the tumorigenesis of hepatocellular carcinoma (HCC). One KCNRG missense mutation, CGT->CAT (Arg->His) was found at codon 92 within the T1 domain. Hep3B hepatoma cells were transfected with the wild- or mutant-KCNRG to determine the effect of this mutation in KCNRG. Interestingly, the suppressive cell growth activity of the mutant-type KCNRG was significantly lower than that of the wild-type KCNRG. In addition, allelic loss was detected in 17 out of 64 (26.5%) informative HCC cases, and all were hepatitis B virus (HBV)-positive. Moreover, the allelic loss was closely related to an intrahepatic metastasis (P=0.0247), higher grade (P=0.0078) and clinical stage (P=0.0071). Expression analysis revealed 22 tumor tissues to have a loss of expression of the KCNRG transcript. These results suggest that genetic alterations and the expression of KCNRG might play an important role in the development and/or progression of a subset of HCCs.