Imaging-Assisted Large-Format Breast Pathology: Program Rationale and Development in a Nonprofit Health System in the United States

Table 4

Percent of surface area available for conventional histopathologic evaluation of surgical margin status. Hypothetical 8.0 cm diameter lumpectomy specimen with one 2.0 cm × 2.0 cm tissue block removed for each of six axial margins. Specimen surface area = 201 cm².

Examination method	Total surface margin area examined (cm^2)	Percent of specimen surface area
En-face, six 2 × 2 cm sections	24 cm^2	12%
Perpendicular, six sections 2 cm of arc × 0.3 cm thick*	3.6 cm^2	1.8%
Perpendicular, six sections 2 cm of arc × 4 microns thick**	0.048 cm^2	0.02%

∗Assumes 6 tissue blocks 2 cm × 2 cm measuring 3 mm thickness each, maximum amount of tissue available for examination in the paraffin block.
**Assumes 6 tissue blocks 2 cm × 2 cm with final section thickness on microscopic slide of 4 microns.