Invasive Micropapillary Carcinoma of the Breast

DefinitionBreast carcinoma with a prominent (pseudo) micropapillary patternDiagnostic CriteriaNumerous small pseudo-papillary clusters of cellsNo fibrovascular coresFrequent central lumen formation in clustersPeripherally located nuclei frequently bulge out with knobby appearance, "the hedgehog" tumorClusters surrounded by clear spacesOne or only a few clusters per spaceScant mucin rarely detectable in spacesSpaces surrounded by loose fibrocollagenous stromaFrequent high nuclear grade reported in some seriesFrequently has abundant eosinophilic cytoplasmFrequent lymphatic involvementOccasional psammoma bodiesAssociated DCIS may be of various typesNot related to micropapillary DCISPattern may be predominant or focalNo clinical difference between predominant and focal casesNo reported cutoff for minimal significant amount of patternReport such cases as mixedFrequently mixed with infiltrating ductal carcinomaRarely mixed with other typeClinicalIncidencePure about 1%Mixed about 4-7%Frequent local recurrence (70-90%)Poor prognosisApproximate 40% dead of disease in three yearsNot independent of stageLinked to high incidence of nodal involvementRare cases reported in malesGrading / Staging / ReportGradingBloom-Scarff-Richardson grading scheme is most widely usedTotal score and each of the three components should be reportedBased on invasive area onlyTubule formationScore>75% tubules110-75% tubules23Nuclear pleomorphism (most anaplastic area)ScoreSmall, regular, uniform nuclei...
Source: Oncopathology - Category: Cancer & Oncology Source Type: blogs