Micropapillary breast carcinoma is a rare variant.

Micropapillary carcinoma of breast has a few unique clinical, microscopic and immunological features which aid in their differentiation from other subtypes of breast carcinoma.

Let’s look at them!!

1. Tufts of cells arranged in pseudopapillae ( lack fibrovascular cores). These pseudopapillae are surrounded by empty clear spaces formed by fibrocollagenous stroma.

Micropapillary breast carcinoma- microscopy

2. Aggressive tumor usually present with angiolymphatic invasion. They present with nodal invasion at the time of presentation.

3. Molecular and cytogenetics: BC-1514 (C21orf118) is commonly upregulated in the micropapillary area.

4. ER positive in 90% and PR positive in 50%

5. Micropapillary breast carcinomas show

‘INSIDE OUT’ staining pattern with EMA and CD15s.

INSIDE OUT staining pattern refers to – staining localized to the apical surface of tumor cells abutting the stroma but absent staining in the basolateral region.

Staining pattern of EMA ( Epithelial membrane antigen) and CD 15s in micropapillary breast carcinoma.

6. Another characteristic of micropapillary breast carcinoma is Incomplete basolateral or CUP SHAPED staining with apical sparing seen with E- cadherin,  Her-2-neu and p-120.

‘Cup shaped’ staining with EMA – stained basolateral surface and apical sparing.

Below is a picture which will help you remember all characteristics of micropapillary breast carcinoma.


1. A 50 year old man presented with mild abdominal pain with mildly raised ALT and AST.  Fatty liver was suspected,  which of the following changes is not seen ultrastructurally in this condition?

A)  Generalized swelling of cell and plasma membrane.

B)  Nuclear changes such as pyknosis,  karyorrhexis and karyolysis are seen.

C) Accumulation of “myelin figures” in the cytosol composed of phospholipids derived from damaged cellular membranes.

D) Dilation of the ER, with detachment of polysomes.

Answer: B.  Pyknosis,  karyorrhexis and karyolysis are classic features of apoptosis

2. What is the mechanism behind plasma membrane swelling in reversible cell injury?

A)  Influx of water due to direct damage to Na-K-ATPase pump

B)  Plasma menrane damage leading to increased leakiness to sodium ion.

C)  Depletion of ATP resulting in oxygen deficiency interfering in Na-K-ATPase pump activity.

D)  All of the above

Answer:  D


Check out this excellent blog  on more knowledge and details on this topic:  https://theartofmed.wordpress.com/2015/05/29/pathologic-cell-injury-and-cell-death-i-mechanism-of-reversible-cell-injuries/amp/


1.Correctly matched with organ and stem cell niche are all except?

A)  Intestine- crypts

B)  Eyes- limbus of cornea

C)  Brain- periventricular zones

D)  Bone marrow- Paratrabecular area

Answer: D- Bone marrow stem cell niche is – peri-sinisoidal region.

2. Which is the true statement

A)  Rb gene is the key regulator of G2M cell cycle transition.

B) Rb is active in hypophospholylated state

C) MDM2 protein activates p53

D)  p53 activation leads to cell cycle progression

Answer: B – is true, Rb is the regulator of G1/S phase, MDM2 protein inhibits p53 and p53 active leads to transient cell cycle arrest.

Yeaterdays questions with updated answers https://pathologymcqforall.wordpress.com/2021/03/28/mcqs-general-pathology-growth-factors-and-receptors-28-3-20/

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1.All are true about receptors with tyrosine kinase activity except?

A) Downstream phosphorylation is a common pathway of signal transduction

B) Changes in receptor geometry can stimulate intrinsic receptor protein kinase activity

C) The cellular homologue of the transforming protein of the Rous sarcoma virus, called Src, is the
prototype of this family.

Answer: C – src is a prototype of non- receptor tyrosine kinase family

2. Which one is matched correctly?

A) EGFR- synonymous to ERB-B2

B) Her-2-neu -ERB-B1

C) TGF-beta- Inflammatory cytokine

D) Hepatocyte growth factor- Scatter factor.

Answer- D – erb-b1 is EGFR, erb-b2 is her2-! and TGF-beta is anti-inflammatory

3. Which of the following is false about collagen ?

A) Collagen I,V and XI are heterotrimers

B) Defects in collagen occur in marfan syndrome

C) Helix formation occurs in the golgi apparatus

D) Cross-linking occurs in the extracellular space

Answer: B- Marfan syndrome is caused by defects in fibrillin

For more questions checkout

Questions and explanations on cellular housekeeping: https://pathologymcqforall.wordpress.com/2021/03/28/general-pathology-mcqs-topic-cellular-house-keeping/

Questions and explanations on genome: https://pathologymcqforall.wordpress.com/2021/03/26/mcqs-general-pathology-genome-26-03-2021/

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