Lipoastrocytoma: Case report and review of the literature.

Lipoastrocytoma is an extremely rare tumor, with only six cases described. We report the case of an astrocytoma involving the upper part of the cerebellar-pontine angle and the right portion of the clivus starting from the brainstem with a diffuse lipomatous component in a 39 year-old man. The patient was admitted with headache of 1 year's duration and diplopia over the previous 3 months. MRI revealed a ponto-cerebellar lesion that showed irregular enhancement after contrast administration. Subtotal excision of the tumor was accomplished. Adjuvant chemotherapy and radiation therapy were not administered. Histologically the tumor showed the classical histology of low-grade astrocytoma and a portion of the lesion was composed of lipid-laden cells. Immunohistochemistry for glial fibrillary acid and S-100 proteins clearly demonstrated the glial nature of these cells. Ki-67/Mib-1 labeling index was low (2%). The patient remains in good neurological conditions after 10 months. Our case has a benign postoperative behavior, also after subtotal excision, with restrictions due to the short follow-up. It is important to record each new case of this rare tumor to produce a better characterization of this lesion.

Ultrastructural morphometry of different adrenal adenoma types.

Twelve surgical specimens of adrenal tumors (3 mainly compact cell adenomas and 2 mainly spongiocytic adenomas of Cushing's syndrome, 4 adenomas of Conn's syndrome, 1 androgen-secreting adenoma, and 2 hormonally inactive tumors) were studied by ultrastructural morphometry, using the point-counting method. All groups were compared with regard to the statistical differences among the different cell organelles. Compact cell adenomas and spongiocytic adenomas in Cushing's syndrome revealed differences in the volume fraction of the following cell organefles: nuclei, smooth endoplasmic reticulum, mitochondria, Golgi zones, and unorganized cytoplasm, as well as in the fraction of lipid vacuoles. Compact cell adenomas in Cushing's syndrome were different from Conn's adenomas with respect to nuclei, smooth endoplasmic reticulum, rough endoplasmic reticulum, lysosomes, Golgi zones, and unorganized cytoplasm. Spongiocytic adenomas in Cushing's syndrome were different from adenomas in Conn's syndrome with respect to organized cytoplasm and lysosomes. Further data are given concerning the differences between Cushing's syndrome, adenomas in androgen-producing tumors, and inactive tumors. The statistically significant data were correlated with the functional expression of the different tumors. The morphometric studies confirmed the visually established ultrastructural features of adrenal tumors and provided further significant differences. Finally, these examinations obviously yielded specific patterns of the different adrenal adenoma types.