This week the case consisted of a breast biopsy. The 36 year-old female presented microcalcifications in her mammogram. Histology showed micropapillary ductal carcinoma in situ (DCIS). Micropapillary structures are seen floating within the lumen of ducts regardless of the nuclear grade.
A-B) Low nuclear grade: numerous club-like micropapillae are formed by monomorphic cells with rounded, uniform, and equidistant nuclei. The chromatin is finely dispersed. Mitotic figures are absent.
C-D) Intermediate nuclear grade: micropapillae of different shapes are formed by cells displaying pleomorphic nuclei with increased nuclear/cytoplasmic ratio, occasional nucleoli, and coarse chromatin.
E-F) High nuclear grade: irregular micropapillae are formed by atypical cells with large, markedly pleomorphic, poorly polarized nuclei and apparent nucleoli. Mitotic figures and necrotic cellular debris are present.
http://www.nature.com/modpathol/journal/v23/n2/full/modpathol2009169a.html