Parapharyngeal lymph node metastasis: an unusual presentation of papillary thyroid carcinoma.
BACKGROUND
Parapharyngeal space nodal metastases are usually secondary to malignancies of the pharynx and sinonasal tract, although localization of lymphomas is also possible. Parapharyngeal metastases arising from thyroid papillary carcinoma are instead an exceedingly rare event, with only 10 cases reported up to now in the literature.


METHODS
We describe two cases of parapharyngeal metastasis from thyroid papillary carcinoma in a man and a woman, aged 40 and 52 years, respectively.


RESULTS
Both patients had a lesion that clinically appeared to be located in the parapharyngeal space; they underwent CT and MRI, which detected a cystic mass in the poststyloid compartment. In the first patient, fine-needle aspiration cytology failed in identifying the histologic nature of the lesion, which was excised through a transcervical approach. A diagnosis of metastatic thyroid papillary carcinoma was rendered and therefore the patient underwent total thyroidectomy. In the second patient, a total thyroidectomy, previously scheduled for multinodular goiter, was performed along with the removal of the parapharyngeal mass. Definitive histologic findings revealed that the two parapharyngeal masses were cystic metastases from a thyroid papillary carcinoma. Both patients received postoperative 131I treatment. Twenty-four months after surgery, the first patient is free of disease, whereas the second one has clear signs of abnormal 131I uptake in the lungs.


CONCLUSIONS
The differential diagnosis of a parapharyngeal poststyloid mass should also include metastasis from thyroid papillary carcinoma. When the lesion displays a cystic appearance on imaging, it is advisable to rule out a thyroid primary by ultrasonographic examination. The occurrence of a metastasis in such unusual site, even though rarely reported, does not seem to significantly affect the prognosis of the disease.
Lombardi
Davide
D
Department of Otorhinolaryngology, University of Brescia, Piazza Spedali Civili, 1, 25123, Brescia, Italy.
Nicolai
Piero
P
Antonelli
Antonino R
AR
Maroldi
Roberto
R
Farina
Davide
D
Shaha
Ashok R
AR
D000328:Adult; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000556:secondary* / Q000601:surgery; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010610:Pharyngeal Neoplasms / Q000556:secondary* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome