In which one of the following head and neck cancer, perineural invasion is most commonly seen:

Adenoid Cystic Carcinoma (Cylindroma) Most common malignant tumor of submandibular glands. Most common minor salivary glands tumour. Most common site minor salivary gland. Characterized by its tendency to invade perineural space and lymphatics and thus causes pain (which may be a prominent and early syniptom) and VII nerve paralysis. Skip lesions along nerves are common. It is a treacherous tumor as it appears benign even when it is malignant. It can metastasize to lymph nodes They are highly recurrent. Local recurrence after surgical excision are common and can occur as late as 20 years after surgery. Distant metastases go to lung, brain and bone. Treatment of choice is radical parotidectomy irrespective of its benign appearance under the microscopy Radical neck dissection is not done unless nodal metastases are present Postoperative radiation is given if margins of resected specimen are not free of tumor