How would you treat an adenoid cystic carcinoma (well-diff, +extensive PNI) of the vulva s/p excision with positive margins?  

Great question. I would not necessarily ask for re-excision, as I don't think it will change the recommendation for post-operative RT to the vulva. There does need to be some kind of inguinal node assessment, and PET is an acceptable approach if the nodes were not sampled or dissected. If PET is neg...

Rare case! I have only treated one case, and as Dr. @Sushil Beriwal wrote, I have extrapolated from head and neck. Such tumors are rarely associated with lymph nodes. They mainly recur locally or distally following nerve routes. In our case, the patient had a 3 cm adenoid cystic carcinoma of the rig...

Rare and have treated only one case extrapolating from head and neck cancer data. I would aim for re-excision if possible and then plan for post op RT to vulva to 60 Gy or so.