bromochloroacetic-acid and Hypopituitarism

To elucidate histological changes in the pituitary gland and adenomas following radiotherapy, two irradiated pituitary glands and seven irradiated non-functioning adenomas were studied. The latter included four cases with conventional radiation (CR) and three cases with radiosurgery: two with gamma knife radiosurgery (GKR) and one with stereotactic fractionated radiotherapy (SRT). The specimens were obtained 10 months to 10 years (mean 58 months) after the radiotherapy. Irradiated pituitary glands showed diffuse fibrosis in the adenohypophysis, whereas irradiated adenomas showed either mild or no fibrosis in five CR/SRT cases and diffuse thick hyaline deposits in two GKR cases. No necrosis was observed. Stellate-shaped S-100 protein-positive cells were greater in number in the irradiated pituitary glands than in the normal glands. Pituitary cells with dense granular reactivity for mitochondrial protein, cytochrome oxidase, and Mn-SOD, mimicking oncocytes, were greater in number in the irradiated adenohypophysis but did not show any change in cell size. Many irradiated pituitary cells and some irradiated adenoma cells were densely positive with anticytokeratin 1,5,10,14 antibody whereas non-irradiated counterparts were negative. In adenomas, MIB-1 labeling index remained unchanged after the radiation. The results may indicate that radiation-induced fibrosis was associated with an increased number of folliculo-stellate cells, mitochondrial dysfunction, and squamous metaplasia. These findings were prominent in irradiated pituitary cells and may participate in delayed pituitary hypofunction following radiotherapy. In irradiated adenoma cells, similar findings were observed but diffuse fibrosis was absent. The histological changes were more intensive in adenomas following GKR than those following CR.

Topics: Adenoma; Aged; Antibodies, Antinuclear; Antibodies, Monoclonal; Female; Fibrosis; Humans; Hypopituitarism; Keratins; Male; Pituitary Gland, Anterior; Pituitary Irradiation; Pituitary Neoplasms; Radiosurgery; S100 Proteins; Superoxide Dismutase

Salivary gland rests occur in the posterior lobe of the pituitary gland near or often communicating with the Rathke's cleft or its cystic subdivisions, and are usually incidental autopsy findings. They are attributed to the oropharyngeal development of the Rathke's pouch and may rarely give rise to salivary gland-like tumors in the sella. We present a pleomorphic adenoma, a rare tumor of the sellar region, that has not been previously recognized in association with Rathke's cleft cyst. It occurred in a 44-year-old man who presented with hypopituitarism and reduced vision. Magnetic resonance imaging showed a sellar mass with suprasellar extension which was totally removed. It consisted of segments of a cyst wall lined by focally ciliated columnar of cuboid epithelium containing goblet cells. An eosinophilic granular material with cholesterol clefts represented the contents of the cyst. Within its wall there was a tumor with ductal structures and non-ductal varied cellular components including hypercellular areas of spindle and ovoid cells forming interlacing fascicles. Individual cells appeared to float in abundant mucinous material. The appearances were those of a salivary gland pleomorphic adenoma arising within the wall of a Rathke's cleft cyst. The myoepithelial nature of non-ductal tumor cells was confirmed with immunocytochemistry. The existence of seromucous glands communicating with the Rathke's cleft remnants, explains the concomitant occurrence of the tumor and the cyst. This rare neoplasm from salivary gland rest should be considered in the differential diagnosis of unusual sellar and suprasellar tumors.

Topics: Actins; Adenoma, Pleomorphic; Adult; Biomarkers; Brazil; Central Nervous System Cysts; Diagnosis, Differential; Glial Fibrillary Acidic Protein; Humans; Hypopituitarism; Immunohistochemistry; Keratins; Magnetic Resonance Imaging; Male; Mucin-1; Neoplasms, Second Primary; S100 Proteins; Salivary Gland Neoplasms; Vision Disorders