I notoced there are some cases of fibroepithelial lesions (biphasic tumor)in our website. I send this case to open the discussion.

Fibroepithelial tumors including fibroadenoma (FA) and phyllodes tumors (PT). The definition and classification of PT are not very agreeable among pathologists. However, they are most common classified as bengin, borderline, or malignant suggested by WHO. Some pathologists use terms of benign, low grade maligant and high grade malignant. These two systems are very similar, borderlin equal to low grade malignant.

Hope you can give your diagnosis and mention why. I assume people may have different oppinions. It is ok.  We just discuss the case.

 Most of people here have an agreenment for this case. The tumor demonstrates leaf-like structures, dense stroma with a little heterologeneous distribution and mild cytologic atypia, and a little increased cellularity, pushing margin with focal irregularity. Mitotic firures are rare (0-1/10 high power fields). Clearly it should be a phyllodes tumor, but not fibroadenoma, even though the tumor is small. Considering all the facts I diagnosed benign phyllodes finally.

Welcome you to share your different oppinion. 

 I am showing you another fibroepithelial lesion.

Case 2:

50 y/f right breast lesion 1.7 cm. excisionaly biopsy specimen.

Fig 1. 20x

Other fig 100x

No mitosis is noticed.

Your diagnosis?

名称：图1
描述：图1

名称：图2
描述：图2

名称：图3
描述：图3

名称：图4
描述：图4

名称：图5
描述：图5

名称：图6
描述：图6

 第1例，同第4楼。

第2例：如果图1和6反映病变的边界情况，它的边界是不清楚的，没有包膜，不好直接诊断纤维腺瘤。

周围病变似乎有硬化性腺病和小叶增生。因此总体上考虑“乳腺增生症伴纤维腺瘤形成趋势”。因为它无指状突起，无亲上皮性生长，无核分裂，无明显异型性，间质密度也不高，所以不考虑叶状肿瘤。

 仔细观察 Case2：图1中，从图中看，病变无包膜，部分为纤维腺病样（右上），(左下)部分粘液样背景中增生的导管，结节状，但无明显分叶状结构。20倍视野可见多个腺体，间质细胞稀疏，无异型性，未见核分裂。

综合考虑：此例为纤维腺病伴局部纤维腺瘤样增生。

 40 y/f with breast mass, 1.2 cm.

Key:

F1-2: 20x

F3. 40x

F4-5: 100x

F6: 400x

F7: 600x

I will go to Boston for USCAP meeting tomorrow and will be back next weekend.

 初步印象是叶状肿瘤，良性。

旧称“叶状囊肉瘤”已被废弃，但它概括了基本的形态特点。

叶状：管内生长的叶状突起

囊：叶状突起拥挤形成裂隙，似囊内生长。有的病变在取材时确实包裹在囊内。

肉瘤：这样概括生物学行为就不对了，哈哈。大多数叶状肿瘤是良性的。

另外还有亲上皮性生长、间质细胞丰富/异型性/核分裂数、边界不清或浸润性等特点，用于分级。

 此例考虑叶状肿瘤。

分叶状突入腔内生长，2层上皮细胞，细胞較纤维腺瘤密集，但密度较低，细胞异型性很轻，有核分裂，但不知多少？，可见脂肪浸润，未见坏死、出血。倾向良性。可否提供患者年龄？

 (2)Histologicalyy, the tumor has intracanalicular fibroadenoma structure  with increased stromal cellularity. Focal fronds of stroma covered by a thin layer of epithelium can be seen.

 (3)stroma cells are bland looking with rare mitosis.

 If the tumor occured in adult patient, I think it is compatible with benign phyllodes tumor.

 Thanks for sharing!

 I mentioned above. 40 years with 1.2 cm demarcated breast mass.

Dood discusssion. Good point to ask the number of mitosis. Metotic figures are rare, 0-1/10 HPF.