Biomedical subjects

T W Shek

Publications and source records attributed to T W Shek.

76 records · Page 5Linked to original sources

PubMedDate not supplied

The pathological basis of resection margin for hepatocellular carcinoma.

At the time of hepatectomy for primary hepatocellular carcinoma (HCC), the necessary amount of surrounding nontumorous liver to be sacrificed, or the resection margin, which will ensure a complete histologic disease clearance is uncertain. Twenty-three resected liver specimens were studied by serial section followed by histological examination prospectively. All histologic diseases identified were assumed to spread radially in all directions from a unicentric lesion. Histologic disease from capsular and liver invasion was found confined to the immediate surrounding liver parenchyma. Eleven of the 14 large (> or = 5 cm) tumors and all six small (< 5 cm) HCCs had either microsatellites and/or histologic venous permeation found beyond 1 cm from the lesion. A large tumor, multinodular lesions, macroscopic venous thrombi, liver invasion, and nonencapsulation were associated with an extensive spread of histologic disease. In the presence of either microsatellites or histologic venous permeation, no distance could ensure a complete disease clearance.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Glomangiomyoma of the nasal cavity.

Glomus tumor is a rare neoplasm that typically occurs in soft tissue of the extremity, particularly the subungual region of the finger tip. It rarely occurs in the nasal septum. Glomangiomyoma is a rare histologic variant of glomus tumor. The authors describe a case of glomangiomyoma of the nasal septum that presented as nasal obstruction. The histologic, immunohistochemical, and electronmicroscopic findings are described. The otolaryngologist and surgical pathologist should be aware of such an entity, and should not confuse it with the totally unrelated glomus jugulare tumor, or paraganglioma of the middle ear.

Adult↗

PubMedDate not supplied

Opacification of artificial intraocular lens: an electron microscopic study.

This paper describes the usefulness of electron microscopy in the investigation of the cause of opacification of an intraocular artificial lens (IOL), which affected both the anterior and posterior surfaces of the IOL. The explanted lenses were remarkably similar and were uniformly opaque, with "reticulated" surfaces under dissecting and ordinary light microscopes. TEM showed that the surfaces of the explanted lenses were irregular, and there was a layer of electron-dense granular deposits that extended to a depth of approximately 5 microm into the lens substance. SEM showed a "cerebriform" lens surface with elevated areas alternating with depressed crevices, which corresponded nicely to the TEM appearance. Energy-dispersive x-ray analysis showed that the deposit was composed of calcium, oxygen, and phosphorus, which was later shown to be calcium hydroxyapatite by x-ray diffraction study. Electron microscopy has proven to be an essential tool in the investigation of the cause of this mysterious outbreak of opacification of the surfaces of the artificial lenses. Apart from directly visualizing the lens surfaces in a 2- and 3-dimensional manner, it also provides information on the elemental composition of the deposit. Such findings enable the clinicians and manufacturer to search for the underlying pathogenesis of the abnormal calcium hydroxyapatite crystals deposit.

Calcinosis↗

PubMedDate not supplied

Diagnostic significance of mitochondria in four types of renal epithelial neoplasms: an ultrastructural study of 60 tumors.

Mitochondrial morphology was studied in 60 renal epithelial neoplasms, including clear cell, papillary, chromophobe cell, and oncocytomas, to see if there are significant differences among the various subtypes. Mitochondria from the nephron tubular system obtained from 36 patients with glomerular diseases served as controls. Significant differences were found in mitochondrial ultrastructure in each of the subtypes of renal epithelial tumors. Novel observations were the presence of tubulovesicular cristae in many of the mitochondria found in chromophobe cell renal carcinomas and the discovery of a possible new oncocytic variant of this entity with mitochondria with pseudotubulovesicular and lamellar cristae similar to those of renal oncocytomas. This latter finding may be of prognostic significance, since renal oncocytomas are benign, while chromophobe cell neoplasms may behave in a malignant fashion.

Adenoma, Oxyphilic↗