RESUMO
INTRODUCTION: Malignant peripheral nerve sheath tumours (MPNSTs) are rare neoplasias, often having progressive growth and an unfavourable outcome. Patients relapse regularly and the tumour metastasizes frequently. Early diagnosis and intense therapy, including radical resection and adjuvant radio- and chemotherapy, are necessary to achieve cure or prolonged survival. CASE REPORT: A woman aged 60 years, survived 137 months from an initial diagnosis of fibroma of the sinus, which later proved to be intracerebral progressive malignant metastasized nerve sheath tumour. DISCUSSION: A literature review and various case reports showed that MPNSTs are generally highly malignant, and often cannot be cured. Patients can be cured if the tumour is completely removed following adjuvant radio- and chemotherapy, depending on the tumour location.
Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias de Bainha Neural/diagnóstico , Biópsia por Agulha Fina , Neoplasias Encefálicas/terapia , Terapia Combinada , Diagnóstico Diferencial , Progressão da Doença , Evolução Fatal , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Neoplasias de Bainha Neural/terapia , Tomografia por Emissão de Pósitrons , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
Receptors for testosterone (T) and dihydrotestosterone (DHT) as well as the tissue specific androgen-5 alpha-reductase (A5R) were studied in the foreskin of 52 healthy boys (ages 1-14 years), in order to gain molecular endocrinological data and information about the ontogeny and cytogeny, respectively, of androgen specific target organs. Enzyme determinations were carried out in tissue homogenates by an enzyme kinetic method for the evaluation of Km- and Vmax-values. Reactions velocities were calculated from the turn over rates of T to DHT, 5 alpha-androstane-3 alpha,17 beta-diol and 5 alpha-androstane-3,beta,17 beta-diol. The precursor (T) was used in increasing concentrations, ranging from 8 to 208 nM. Separation of reaction products was done by thin-layer chromatography and verification of specific radioactivity of metabolites by means of radio gas chromatography on capillary columns. Results of the enzyme analyses: Km = 94.9 +/- 3.5 [nM], and Vmax = 15.8 +/- 1.9 [pmol/mg.h]. Receptors were examined in the cytosolic and nuclear fractions of the tissue specimens. Saturation analyses and calculation of binding data led to specific receptors for T and DHT in the cytosolic (T: Kd = 1.56 +/- 0.12 [nM], Nmax = 122.4 +/- 11.6 [fmol/mg]; DHT: Kd = 1.9 +/- 0.1 [nM], Nmax = 493.3 +/- 77.8 [fmol/mg]) and the nuclear fractions (T: Kd = 1.43 +/- 0.13 [nM], Nmax = 28.7 +/- 3.5 [fmol/mg]; DHT: Kd = 1.37 [nM], Nmax = 196.9 +/- 22.5 [fmol/mg]), Kd-values proved to be quite homogenous (coeff. var. = 0.15-0.21), whereas maximum specific receptor binding activities (Nmax) showed age dependent fluctuations (coeff. var. = 0.35-0.45). Binding capacities of both T- and DHT-receptor, respectively, in cytosolic and nuclear fractions showed peak values in the age group 10-11 years and additional "spikes" of binding rates at age 4-5 years. It is noteworthy that Vmax-values also reached maximum levels in the latter age group. Concerning the ontogeny of the androgen receptor a change of binding properties from the cytosol to the nuclear fraction was observed with the onset of puberty. A comparison of enzyme- and receptor data lead to the theory, that subcellular hormone actions depend on interrelational regulatory mechanisms between androgen receptors (T as well as DHT) and specific enzyme systems (A5R).