I do NOT see the typical fibrilary chondroid-myxoid stroma in this case, so I could not call this case pleomorphic adenoma. I decided to sign out as " a low grade epithelial neoplasm", recommend excision. It turned out to be a very good case of ????, Can you guess?

 I have the surgical resection of this tumor and will post soon.

 I have the surgical resection of this tumor and will post soon.我有组织学切片，不久会帖出来供大家欣赏。

Here is the histology of the resection. Thanks!

好病例，学习。陈博士给的最后答案是多形性低级别腺癌，陈博士细胞发的报告是：I decided to sign out as " a low grade epithelial neoplasm", recommend excision。低级别上皮性肿瘤建议手术切除。

这样的发报告非常客观，好！因为肿瘤细胞异形性不大，但是可以肯定是一个腺上皮低级别肿瘤，详细分类不容易。就这样发细胞穿刺报告非常好。手术下来再细分类。

 I feel that this case is very difficult and I would like to summarize it:

 1) Polymorphous low-grade adenocarcinoma (PLGA) is found almost exclusively in minor salivary gland. It is a low-grade malignancy with generally good prognosis. It is commonly present in patients aged 50-70 year-old with female affected twice as frequently as men (our patient is a 61-year-old woman).

2) PLGA is cytologically uniform, but architecturally diverse: it can be lobular, solid nests, cribriform, or papillary. It is usually infiltrative with perineural invasion. The bluish stroma in the background is typical and it is different from the chondroid myxoid stroma found in pleomorphic adenoma (PA);

3) The differential diagnosis of PLGA mainly includes PA and adenoid cystic carcinoma (ACC). Because PLGA has diverse architectural appearance, it is very difficult to diagnose on FNA and most of times are not possible even on small excisional biopsy. This patient had a small excisional biopsy almost 10 years ago and was called PA, but we get the outside slides and it is almost identical to the current resection specimen, also showed perineural invasion.

4) This case brought a very important concept that I would like to share with our chinese pathologists on ipathology. Salivary gland FNA can be very difficult, if a FNA sample does not fit perfectly in a disease category, I would have no hesitation to issue the report with "Atypical cells present" and a comment recommend excision. In this case, on the FNA, I don't see the typical chondroid-myxoid stroma, so I would not just sign out the case as "pleomorphic adenoma".

5) To be a good cytopathologist, we have to know our limitation and the clinical management, as most of the salivary gland tumors will be clinically taken out surgically anyway except some Warthin tumors, metastatic tumors, and lymphoma. So, if you can tell the clinician that this is most likely a low-grade salivary gland neoplasm (not Warthin tumor or lymphoma or metastatic tumor), the clinical management usually is similar.