A 50-year-old man comes to the office due to a lump in his neck that has been present for 4 months and is enlarging. On examination, there is a firm, nontender, nonmobile mass in the right anterior neck. Otoscopic examination shows a clear right middle ear effusion. Needle biopsy of the neck mass is consistent with regional nodal spread of squamous cell carcinoma. Which of the following is the most likely site of the primary tumor?

Question

A 50-year-old man comes to the office due to a lump in his neck that has been present for 4 months and is enlarging.  On examination, there is a firm, nontender, nonmobile mass in the right anterior neck.  Otoscopic examination shows a clear right middle ear effusion.  Needle biopsy of the neck mass is consistent with regional nodal spread of squamous cell carcinoma.  Which of the following is the most likely site of the primary tumor?

Quizplus · Accepted Answer

11ec160b_356b_ef92_9249_bba5803eaff6_MD0001_00 Squamous cell carcinoma that originates in the mucosa of the head and neck typically spreads first to the anterior cervical lymph nodes. An enlarged, firm cervical lymph node is often the presenting symptom of head and neck squamous cell carcinoma (HNSCC). Identification of the primary site of tumor formation is important for staging and to guide treatment strategies. This patient's unilateral middle ear effusion suggests obstruction of the eustachian tube, which connects the middle ear space to the nasopharynx. It opens intermittently, typically during swallowing or yawning to equalize pressure in the middle ear. Failure to adequately open causes negative pressure to build within the middle ear, leading to a transudative effusion (clear, amber, or yellow). Eustachian tube dysfunction can be due to anatomic obstruction from a mass in the nasopharynx or, more commonly, due to functional obstruction from infections, allergic rhinitis, or irritants (eg, tobacco smoke). (Choices A, D, and F) HNSCC can originate from the mucosa of other anatomic sites. Many sites (eg, base of tongue, piriform sinus) initially cause only vague or minor symptoms, but some may present with more specific features (eg, hoarseness in vocal cord cancer). Cancer at any of these other sites (ie, base of tongue, piriform sinus, vocal cord) would not lead to obstruction of the eustachian tube with a resultant middle ear effusion. (Choice C) Cancer of the parotid gland may spread to the cervical lymph nodes. The superior portion of the parotid gland is near the external auditory canal of the ear, not the eustachian tube. In addition, because the parotid gland is near the skin surface, primary tumors of the parotid are typically palpable. (Choice E) Cancer of the thyroid gland may spread to the cervical lymph nodes. However, it is very rare to have squamous cell carcinoma in the thyroid, and enlargement of the thyroid gland would not block the eustachian tube. Educational objective: The eustachian tube connects the middle ear to the nasopharynx. Cancer located in the nasopharynx can lead to obstruction of the eustachian tube, causing a middle ear effusion.

A 50-Year-Old Man Comes to the Office Due to a Lump