Availability and quality of paraffin blocks identified in pathology archives: A multi-institutional study by the Shared Pathology Informatics Network (SPIN)

Table 10 Average size of tumor present in tissue blocks. The average size of tumor present on the blocks for rare tumor types retrieved and reported from a pool of 400 cases from all SPIN centers. Rare Tumors

Tumor Size	Largest block containing tumor (cm)	2nd largest block with tumor (cm)	3rd largest block with tumor (cm)
n	286	221	167
AVERAGE	1.555	1.523	1.596^{^}
MAX	2.6	2.7	2.8
MIN	0.1	0.1	0.1
STDEV	0.854	0.820	0.726

^{^}The average size is based on all cases that reported the third block. Cases with large volume tumors had many blocks with large sizes of tumor (≥3 blocks), whereas, small volume tumors had fewer blocks with tumor available (< 3 blocks). The total number of the 3^rd block with the presence of tumor was many from large volume tumors, thus the higher average size compared to largest block #1.

ISSN: 1471-2407