Tissue microarray construction for salivary gland tumors study

Abstract

Objective: To describe and discuss the design, building and usefulness of tissue microarray (TMA) blocks for the study of salivary gland tumors (SGTs).

Study design: Two hundred thirty-eight formalin-fixed, paraffin-embedded SGTs were arranged in blocks of TMA using a manual tissue arrayer. Three representative cores of 1.0, 2.0 or 3.0mm were taken from each original block and their characteristics were analyzed and described.

Results: It was created 12 TMA blocks that presented highly representative neoplastic cylinders. However, those neoplasias rich in cystic spaces such as mucoepidermoid carcinoma and Warthin tumor presented more difficulties to be sampled, as the neoplastic tissue available was scarce. Tissue damage and loss during TMA construction was estimated as 3.7%.

Conclusion: Representative areas of SGTs, with relatively small loss of tissue, can be obtained with the construction of TMA blocks for molecular studies. However, tumors rich in cystic spaces present more difficulties to be adequately sampled.

Figure 1

Example of full tissue sections previously and after the acquisition of TMA cores of A) 1.0, B) 2.0 and C) 3.0 mm. It can be seen that sections that provided larger cylinders became significantly more damaged than those that provided smaller cylinders. Microscopic images acquired using the Aperio ScanScope CS scanner.

Figure 2

Highly representative areas of pleomorphic adenoma in tissue cores of 1.0, 2.0 and 3.0mm.

Figure 3

In cases rich in cystic spaces as low-grade mucoepidermoid carcinoma and Warthin tumor, only few neoplastic tissue are found on the TMA cores.