Table 2.

Immunohistopathology Subset—Review of Regression, Immune Cell Infiltration, and Incidence of Lymphoid Structures

		Regression					Immune cell infiltration
Group number	N	0% of nodules	1%–10% of nodules	11%–50% of nodules	>50% of nodules	Complete regression	Mild	Moderate	Marked	TLS per low power
1	2	2					2			0.5–1
2	3	1	1		1		1	2		1
3	3		1		2			1	2	3
4	3		1		1	1		2	1	2
5	3				3			2	1	2
6	3				2	1a		2	1	2

AE1/AE3⁺ staining highlighted tumor regression by the progressive loss of tumor cells at the periphery of tumor nodules resulting in irregular borders associated with increased immune cell infiltration, semiquantitatively graded as CD11b⁺ staining density: Mild (patchy distribution of scattered immune cells that are mostly single spaced); Moderate (increased density of immune cells that includes single-spaced individual cells and increased dense clusters of immune cells); and Marked (prominent and extensive immune cell infiltration that includes numerous dense collections of immune cells).

^aResidual keratin-positive structures were noted in one case; unable to distinguish between rare carcinoma cells or regenerative or atrophic entrapped blood vessels or alveoli. TLS per low-power field: 4 × objective and 10 × ocular.

TLS, tertiary lymphoid structures.