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5 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Invasive micropapillary carcinoma is a rare type of breast cancer in which small clusters of cells float inside-out in empty spaces. It spreads to the lymph nodes far more often than ordinary breast cancer of the same size, but once that is allowed for its survival is similar, and it is treated by receptor status like other breast cancer, usually hormone-driven.
The WHO classification defines invasive micropapillary carcinoma by morule-like clusters of cells without fibrovascular cores lying in clear stromal spaces, with reversed polarity shown by the inside-out staining of epithelial membrane antigen and sialyl Lewis X (Tan 2020; Archives of Pathology 2016). It is a variant of luminal B breast cancer, hormone-receptor positive with HER2 positivity in a proportion, with frequent lymphovascular invasion and nodal metastasis; molecular studies show distinct profiles supporting its status as an entity but no single genomic aberration explaining its morphology (Archives of Pathology 2016). Laboratory work using MCF7 spheroids modelled the chemoresistance described in the tumour through HIF-1-driven P-glycoprotein expression (BMC Cancer 2012).
How it differs from its parent: its nodal spread is out of proportion to its size, so imaging of the axilla and node surgery matter more; mixed tumours (micropapillary with no special type) are common and the threshold for calling a tumour micropapillary is not agreed.
| Setting | Approach | Guideline |
|---|---|---|
| All stages | Treated by receptor status on the parent's pages, with careful axillary staging. | not mapped |