Abstract
Background
The differential diagnosis of facial anesthesia is vast. This may be secondary to trauma, neoplasm, both intracranial and extracranial, infection, and neurologic disease. When evaluating a patient with isolated facial anesthesia, the head and neck surgeon often thinks of adenoid cystic carcinoma, which has a propensity for perineural invasion and spread. When one thinks of head and neck squamous cell carcinoma with or without unknown primary, the typical presentation involves dysphagia, odynophagia, weight loss, hoarseness, or more commonly, a neck mass. Squamous cell carcinoma presenting as facial anesthesia and perineural spread, with no primary site is quite rare.
Methods
Case presentations and review of the literature.
Conclusions
Trigeminal anesthesia is an uncommon presentation of head and neck squamous cell carcinoma with unknown primary. We present two interesting cases of invasive squamous cell carcinoma of the trigeminal nerve, with no primary site identified. We will also review the literature of head and neck malignancies with perineural spread and the management techniques for the two different cases presented.
1
Introduction
Facial numbness may be a manifestation of multiple diseases processes. In the acute setting one may consider intracranial processes, such as cerebrovascular accident, tumors, migraine, or demyelinating diseases. In those presenting with chronic progressive numbness, neoplastic or infiltrative processes become more likely. In the head and neck, paranasal sinus tumors and cutaneous malignancies are known to cause facial numbness as the neoplasm begins to infiltrate portions of the trigeminal nerve. Adenoid cystic carcinoma is most notorious for perineural spread, and is typically at the top of the differential diagnosis for neoplasm causing facial anesthesia.
Squamous cell carcinoma is an unlikely culprit for isolated trigeminal nerve invasion, particularly when there is no primary site identified. Unknown primary squamous cell carcinoma in the head and neck region, most commonly presents with metastasis, as a neck mass, with primary sites the ipsilateral tonsil in 20–40% of cases, followed by the base of tongue . A full work up, including imaging, biopsy, and panendoscopy is necessary to determine the source and treatment options.
2
Case presentations
2.1
Case 1
A 56 year-old male was seen in consultation for a 2-year history of progressive right facial numbness, headaches, and trigeminal neuralgia. The anesthesia began on the right side of the tongue, shortly after a tongue lesion biopsy, which demonstrated lichen planus. This then progressed to incorporate the right buccal mucosa, and later the right facial skin extending to the auricle and occipital region. He endorsed stabbing pain in the V2 distribution exacerbated by touching the face. This had been previously been treated with Lyrica® (Pregabalin) and Trileptal® (Oxcarbazepine), which improved his symptoms somewhat. He presented due to recent increase in severity of headaches, now more constant in nature. To evaluate these symptoms a rheumatologic work up was performed at an outside hospital, which returned negative; therefore, his care was transferred to our tertiary care center. His medical history was positive only for chronic obstructive pulmonary disease. He was a poor historian and previous records were not available, but he had undergone a right tonsillectomy in the past, which showed dysplasia, no malignancy. He had a significant smoking and alcohol history, nearly 50 pack years and 4–5 drinks per day. He had a 15-lbs weight loss in the past 6 months, but otherwise denied dysphagia, odynophagia, hoarseness, or otalgia.
Upon physical examination his physical exam was notable for anesthesia of the right hemi-face, with abrupt transition to normal sensation at the midline. The anesthesia extended posteriorly to the occiput. There was visible atrophy of the right temporalis and masseter muscles. There was no palpable midface masses or cutaneous lesions, though he did have ulceration of the skin of the right oral commissure. The oropharyngeal and oral cavity exams were otherwise normal, and there were no appreciable neck masses.
An MRI Head with contrast was performed which demonstrated a mass of the right trigeminal nerve in Meckel’s cave, with extension along the maxillary (V2) and mandibular (V3) divisions of the nerve, with secondary fatty denervation atrophy of the right temporalis, masseter, and medial and lateral pterygoid muscles. (see Fig. 1 ). The V2 and V3 divisions were thickened, with widening of foramen rotundum and ovale, respectively. There was no obvious neoplasm identified in the head and neck. There was also a ring enhancing mass centered at the infundibulum with involvement of the floor of the third ventricle and extension to the pituitary gland (this finding was later deemed unrelated, but did factor into the differential diagnosis). A CT sinus was also obtained with image guidance protocol in preparation for an endonasal approach to biopsy the pterygopalatine fossa for biopsy.
The patient was then taken to the operating room to obtain a tissue diagnosis. As the extracranial portion of the intraorbital nerve was noted to be thickened on the MRI, a sublabial approach was chosen. This allowed direct access to the anterior face of the right maxillary sinus and the infraorbital nerve as it emerged from the infraorbital foramen. The nerve itself was noted to be significantly enlarged, causing subsequent widening of the foramen. A 1 cm length of nerve was excised and sent fresh to pathology. This returned positive for squamous cell carcinoma with extensive perineural invasion.
Given the pathology findings, a CT chest was performed as part of an unknown primary workup, which was negative for malignancy. The patient was then taken back to the operating room for nasal endoscopy, direct laryngoscopy, biopsy of right tonsillar region, rigid esophagoscopy, and right oral commissure biopsy. The panendoscopy was normal. The right oral commissure biopsy showed actinic changes with no malignancy, and the right tonsillar fossa showed mild to moderate squamous dysplasia, but again no malignancy. With a negative workup for a primary, the patient was referred to the Medical Oncology team, where palliative chemotherapy and radiation was recommended.
2.2
Case 2
A 76 year-old male presented in evaluation for 4 months of progressive right midfacial pain extending towards the orbit. He was evaluated by a neurologist, and was prescribed Neurontin® (Gabapentin), which offered mild relief in pain. He subsequently developed right facial anesthesia and a firm mass of the right midface. He had no smoking or alcohol history. His medical history was positive for previous stroke (with no sequelae), hypertension, hypothyroidism and left sided facial skin cancer, of which he did not know the details. He denied weight loss dysphagia, odynophagia, hoarseness, or otalgia. An outside hospital ultrasound-guided fine needle aspiration of the mass was suggestive of adenocarcinoma.
On physical exam he had a nondiscrete firm tender mass of the right midface, with some increased vascularity of the overlying skin, but no ulceration or other concerning skin changes. There was decreased sensation involving the right V2 distribution. The facial nerve was intact, and the remainder of the physical exam was normal, including oral cavity, oropharyngeal, and neck exams. A CT orbit showed a soft tissue mass widening the right infraorbital nerve and foramen (see Fig. 2 ). Subsequent MRI head showed diffuse enlargement of the V2 branch of the right trigeminal nerve extending from the pterygopalatine fossa through the infraorbital foramen, with no intracranial extension. Outside PET CT showed no metastatic disease or primary neoplasm.
As in the previous case, based on imaging findings, a sublabial approach to the infraorbital nerve was used to obtain a biopsy of the nerve, which returned as well-differentiated invasive squamous cell carcinoma. At post-operative follow up he began having new onset right-sided referred otalgia and weakness of the right buccal and zygomatic branches of the facial nerve with sparing of the forehead. At this point it was determined that the facial nerve was likely now involved via retrograde perineural spread. As the patient was exhibiting signs of rapid progression, with no intracranial extension, surgery was offered. Of note, one week later, the temporal branch of the facial nerve had become involved.
The patient underwent resection of the infraorbital nerve squamous cell carcinoma with a right partial maxillectomy via a Weber-Ferguson incision, as well as orbital floor reconstruction, as tumor was involving the orbital floor and pterygopalatine fossa. Pathology confirmed the original diagnosis, with no cutaneous malignancy on histology. He then completed postoperative adjuvant radiation therapy.
2
Case presentations
2.1
Case 1
A 56 year-old male was seen in consultation for a 2-year history of progressive right facial numbness, headaches, and trigeminal neuralgia. The anesthesia began on the right side of the tongue, shortly after a tongue lesion biopsy, which demonstrated lichen planus. This then progressed to incorporate the right buccal mucosa, and later the right facial skin extending to the auricle and occipital region. He endorsed stabbing pain in the V2 distribution exacerbated by touching the face. This had been previously been treated with Lyrica® (Pregabalin) and Trileptal® (Oxcarbazepine), which improved his symptoms somewhat. He presented due to recent increase in severity of headaches, now more constant in nature. To evaluate these symptoms a rheumatologic work up was performed at an outside hospital, which returned negative; therefore, his care was transferred to our tertiary care center. His medical history was positive only for chronic obstructive pulmonary disease. He was a poor historian and previous records were not available, but he had undergone a right tonsillectomy in the past, which showed dysplasia, no malignancy. He had a significant smoking and alcohol history, nearly 50 pack years and 4–5 drinks per day. He had a 15-lbs weight loss in the past 6 months, but otherwise denied dysphagia, odynophagia, hoarseness, or otalgia.
Upon physical examination his physical exam was notable for anesthesia of the right hemi-face, with abrupt transition to normal sensation at the midline. The anesthesia extended posteriorly to the occiput. There was visible atrophy of the right temporalis and masseter muscles. There was no palpable midface masses or cutaneous lesions, though he did have ulceration of the skin of the right oral commissure. The oropharyngeal and oral cavity exams were otherwise normal, and there were no appreciable neck masses.
An MRI Head with contrast was performed which demonstrated a mass of the right trigeminal nerve in Meckel’s cave, with extension along the maxillary (V2) and mandibular (V3) divisions of the nerve, with secondary fatty denervation atrophy of the right temporalis, masseter, and medial and lateral pterygoid muscles. (see Fig. 1 ). The V2 and V3 divisions were thickened, with widening of foramen rotundum and ovale, respectively. There was no obvious neoplasm identified in the head and neck. There was also a ring enhancing mass centered at the infundibulum with involvement of the floor of the third ventricle and extension to the pituitary gland (this finding was later deemed unrelated, but did factor into the differential diagnosis). A CT sinus was also obtained with image guidance protocol in preparation for an endonasal approach to biopsy the pterygopalatine fossa for biopsy.
