RESUMO
Primary Central nervous system lymphoma is a rare non-Hodgkin's tumor of the brain that has been traditionally found in patients with immunodeficiency syndromes. However, there are several immunocompetent patients that have also been reported with this neoplasm. In this group of patients, the mean age of diagnosis is around 60-year old, with a very slight predominance in women. Macroscopically, most of the tumors are unique and mainly located in the supratentorial region in the proximity of the cerebrospinal fluid circulation. The typical histological pattern is a perivascular distribution of tumor cells, within a network of reticulin fibers. Even though they are usually well defined masses, it is not rare to find tumor invasion beyond the macroscopic margin. Coagulative necrosis is not as common as in immunodeficiency-related cases. Immunohistochemistry has demonstrated that most of the tumor cells are B-lymphocytes and the electron microscopic findings do not differ from those reported in systemic non-Hodgkin's lymphomas. There are several histological classifications of these tumors, some of them with recent modifications to facilitate the analysis, but unfortunately, up now with a little or no clinical significance. The diagnosis is based on the histological study of the specimen obtained mainly through a Stereotactic biopsy. The treatment is based on a combination of chemotherapy followed by radiotherapy, but the mortality rate is still high.
Assuntos
Neoplasias do Sistema Nervoso Central/diagnóstico , Linfoma de Células T/diagnóstico , Antimetabólitos Antineoplásicos/uso terapêutico , Neoplasias do Sistema Nervoso Central/líquido cefalorraquidiano , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/terapia , Terapia Combinada , Humanos , Linfoma de Células T/líquido cefalorraquidiano , Linfoma de Células T/patologia , Linfoma de Células T/terapia , Imageamento por Ressonância Magnética , Metotrexato/uso terapêuticoRESUMO
Pituitary collision tumors are rare. They may create difficult diagnostic problems and their histogenesis is not clear. We report here an unusual case of a somatotroph adenoma colliding with a gonadotroph adenoma.The 64-year-old man had clinical acromegaly. His blood growth hormone level was elevated and magnetic resonance imaging demonstrated a pituitary tumor. The surgically removed sellar mass was investigated by histology, immunocytochemistry and electron microscopy. Morphologic study revealed a collision tumor; one was a somatotroph adenoma, the other a gonadotroph adenoma. Authors call attention to the difficulties in clinical, imaging and pathological diagnosis. Detailed morphologic studies are needed to establish the presence of two distinct tumors composed of two different cell types.
Assuntos
Adenoma/diagnóstico , Hormônio Foliculoestimulante/metabolismo , Hormônio do Crescimento Humano/metabolismo , Hormônio Luteinizante/metabolismo , Neoplasias Primárias Múltiplas/diagnóstico , Neoplasias Hipofisárias/diagnóstico , Acromegalia , Adenoma/metabolismo , Adenoma/patologia , Grânulos Citoplasmáticos/patologia , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Neoplasias Primárias Múltiplas/metabolismo , Neoplasias Primárias Múltiplas/patologia , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologiaRESUMO
Hypothalamic gangliocytomas have been shown to contain immunoreactivity for hypophysiotropic peptides and some have been associated with endocrine dysfunction. Extrahypothalamic gangliocytomas are usually not associated with endocrine abnormalities. We studied nine cerebral or cerebellar gangliocytomas from six men and three women; none of the patients had detectable alterations of endocrine homeostasis. On histological examination, the tumor cells resembled hypothalamic neurons. Electron microscopy disclosed the presence of dense-core vesicles in neuronal cytoplasm and processes resembling Herring bodies, and there were synaptic contacts between tumor cells. All but two tumors contained immunocytochemical positivity for at least one peptide hormone or amine; these included somatostatin, corticotropin-releasing hormone, beta-endorphin, galanin, vasoactive intestinal peptide, calcitonin, serotonin, catecholamines or met-enkephalin. These tumors have been thought to represent neoplasms arising in ectopic autonomic neural tissue. Their morphological features, their similarity to hypothalamic gangliocytomas and the multiple immunoreactivities shown here suggest that they can be regarded as tumors of peptidergic neurons that are widely distributed throughout the central nervous system.
Assuntos
Neoplasias Encefálicas/patologia , Neoplasias Cerebelares/patologia , Ganglioneuroma/patologia , Adolescente , Adulto , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/metabolismo , Neoplasias Cerebelares/diagnóstico , Neoplasias Cerebelares/metabolismo , Feminino , Ganglioneuroma/diagnóstico , Ganglioneuroma/metabolismo , Humanos , Imuno-Histoquímica , Lactente , Imageamento por Ressonância Magnética , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
A 48-year-old man with visual disturbances and subtle features of acromegaly had elevated serum thyrotropin (thyroid-stimulating hormone) levels but was clinically euthyroid and initially had normal blood growth hormone (GH) levels. A computed tomographic scan documented a large pituitary tumor; he underwent incomplete transsphenoidal adenomectomy. Postoperative octreotide treatment failed to shrink the tumor. Rising GH levels necessitated repeated transsphenoidal and, subsequently, frontotemporal resection. By histology, the tumor was a chromophobic adenoma. In the first specimen, immunocytochemistry localized GH, beta-thyrotropin, and alpha-subunit of glycoprotein hormones in adenoma cells. The second specimen also contained prolactin, whereas the third contained only GH and beta-thyrotropin. By electron microscopy, the tumor was bimorphous, composed of elongated thyrotrophs and densely granulated somatotrophs. In tissue culture, the first specimen released GH, thyrotropin, and alpha-subunit and smaller quantities of prolactin; the second specimen released only GH and alpha-subunit; and the third released GH, thyrotropin, alpha-subunit, and prolactin. Incubation with somatorelin (GH-releasing hormone) variably stimulated release of all four hormones in the first and third specimens; protirelin (thyrotropin-releasing hormone) had no effect. Somatostatin consistently inhibited release of all four hormones; inhibition by bromocriptine mesylate was variable. The mild degree of clinical and biochemical acromegaly is unusual for a large macroadenoma, and the reasons for the absence of hyperthyroidism are unclear. These discrepancies may be attributed to retarded hormone release and/or synthesis due to suppression by somatostatin in vivo.