Referred otalgia in patients with thyroid cancer: Case series from Saudi Arabia

Abstract

Introduction and importance

Referred Otalgia is very unlikely to be the first presentation of thyroid carcinoma, however, it is important to examine thyroid in cases of otalgia lacking any evidence of primary origin.

Case presentation

We report five cases of thyroid carcinoma, variant types, presented by secondary otalgia in Al-Baha region, KSA followed by proper surgery and patient relief during the last eight years. Patients' ages ranged from 25 to 65 years old.

Clinical discussion

Thyroid inflammation, including acute and subacute thyroiditis, was reported as a possible cause of the pain referred to the ear and the angle of the mandible, however otalgia caused by thyroid cancer is an extremely rare presentation.

Conclusion

Otolaryngologists should be aware that thyroid cancer may be associated with otalgia in any age group, however extremely rare. With very limited sources for this clinical entity, we recommend further studies on the different varieties of thyroid cancer presentations and the possibilities of the unexplained otalgia.

Highlights

• •Otalgia is a very common presentation in ENT clinics, however referred otalgia is relatively uncommon.
• •However, extremely rare entity in the literature, otalgia may be the first symptom of thyroid cancer.
• •Herein we report 5 cases of referred otalgia with underlying thyroid cancer.

1. Introduction

Otalgia is ear pain, which can be primary (originated from a pathology inside the ear) or referred pain (from outside the ear), called referred otalgia [1].

Primary otalgia is a common and unpleasant experience affecting people of different ages; however, it is far more common in children than in elderly patients [2]. When dealing with patients with otalgia, taking the case history by the clinician is the first step at the clinic, followed by physical examinations, paraclinical measures (if necessary), and related consultations with other medical fields [3].

In the case of a normal-looking ear following a careful examination, otalgia is defined as secondary or referred otalgia. Referred pain results from nerve compression or irritation, with the pain usually arising in the region of somatic dermatomal innervation. The otolaryngologist therefore has to have a comprehensive understanding of the complex neuroanatomic innervation that supplies the middle and external ear [2,4]. These converging neural pathways from the affected ear and other organs result in numerous potential causes of referred or secondary otalgia, including oral and dental causes (e.g., temporomandibular disorder, toothache), sinusitis, upper airway infection, laryngopharyngeal reflux, cervical spine pathology, or head and neck malignancy [5].

Head and neck malignancy is prevalent in the Kingdom of Saudi Arabia and worldwide, and the Global Cancer Observatory ranked thyroid cancer as the 3rd most common type in Saudi Arabia [6,7]. The most common presentation in thyroid cancer is either neck swelling (seen by the patient or detected by a clinician) or incidentally detected nodules on neck imaging; however, malignancy should be suspected of the thyroid nodule if it suddenly increases in size with pressure symptoms including hoarseness of voice, dyspnea, dysphagia, or Horner's syndrome, in addition to the family history of thyroid cancer [8,9].

According to the literature, it is very unlikely for thyroid neoplasms to be presented by referred otalgia [10]. This study presents five patients who were presented with ear pain without primary cause and confirmed thyroid carcinoma after careful examination and proper management.

2. Presentation of cases

All patients presented at the ENT clinics at Al-Baha region general hospitals with deep-seated ear pain (otalgia), and a thorough clinical examination aided by otomicroscopy was unremarkable for ear pathology or TMJ lesions. Fiberoptic nasolaryngoscopies and laboratory tests for all patients were also normal. Oral cavity inspection showed no signs of inflammation. Primary causes for otalgia were excluded, and the pain completely subsided after surgery, and patients remained pain-free at 2-week follow-up. The otalgia for all patients was associated with thyroid nodules suggesting direct effect of the nodules on the recurrent laryngeal nerve or might be caused by either invasion or irritation. The clinical features and final diagnoses of the patients were as follows:

2.1. Patient 1

A 28-year-old female with a gradually increasing right neck mass without other complaints. A neck examination showed a 1.5 × 1 cm firm, nontender swelling in the right midjugular area. US examination revealed multinodular thyroid measured up to 1.3 × 09 cm, TIRAD 3. In the right lower lobe with other all-sub-centimeter benign-looking bilateral nodules. FNAC Bethesda III FLUS (Fig. 1). There is no past history of radiation exposure or a positive family history of benign thyroid nodules. A right hemi thyroidectomy was decided and performed with neuromonitoring. During the operation, we found adhesion in the lower lobe to the trachea and esophagus with difficulties of dissection, although the nodule was small. Post-operatively, the right recurrent laryngeal nerve was paralyzed and managed with consultation. The final histopathology examination report showed an insular pattern of papillary thyroid carcinoma (PTC) measuring 1.2 cm in the greatest dimension.

Fig. 1.

FNAC smear showing follicular lesion with scanty colloid.

2.2. Patient 2

A female patient 65 years old with right neck mass associated with nagging right otalgia. The nodule was radiologically diagnosed as TIRAD 5 on US examination, followed by a CT scan (Fig. 2). A total thyroidectomy with central neck dissection and neuromonitoring was done, and 12 positive lymph nodes with bilateral normal recurrent laryngeal nerves were seen. Histological examination revealed a poorly differentiated thyroid carcinoma with a trabecular pattern. A radioactive iodine scan after 4 weeks showed no evidence of any thyroid residue. The patient is being treated with thyroxine supplementation and regular follow-up.

Fig. 2.

A CT scan showing thyroid nodule.

2.3. Patient 3

A 25-year-old nurse presented with bilateral thyroid masses that showed thyroid nodules up to 1.5 cm (TIRAD 3) on US examination. FNAC was done and reported as a Bethesda system category III (atypia) for the thyroid lesion and a suggestive positive lymph node metastasis. A total thyroidectomy with neck dissection (Fig. 3) and neuromonitoring were performed, then sent for histopathology examination, which revealed papillary carcinoma, a classic type with lymph node metastasis.

Fig. 3.

Intraoperative image from the thyroidectomy procedure.

2.4. Patient 4

A 45-year-old female was examined and revealed a left thyroid nodule measuring 2 cm. The US showed a TIRAD-4 lesion, and FNAC was performed, reporting category IV according to the thyroid Bethesda system. The patient was counseled regarding her need for surgery and underwent a total thyroidectomy. Histopathology showed a follicular neoplastic nodule with invasive features suggestive of follicular carcinoma (Fig. 4).

Fig. 4.

A histopathological picture of follicular carcinoma nodule showing invasion.

2.5. Patient 5

This was a male patient, 33 years old, whose examination revealed a right thyroid nodule measuring 3 cm. The US exam showed a TIRAD 5, and FNAC features were clear for malignancy based on the nuclear features of cytological papillary carcinoma. A total thyroidectomy and prophylactic central neck dissection operation were performed, and pathological examination revealed papillary carcinoma, a classic variant with 0–18 free lymph nodes (0–18); however, the size of the nodule was 4 cm on gross examination. A radioactive iodine scan after 4 weeks showed no evidence of any thyroid residue. The patient is being treated with thyroxine supplementation and regular follow-up.

This article is written in line with the PROCESS guidelines [11].

3. Discussion

Approximately forty-four thousand new thyroid cancer cases are diagnosed in the US each year, with a 5-year relative survival rate of 98.5 %. Surgical excision is curative in most cases of thyroid cancer, particularly the well-differentiated types [12].

The Saudi National Cancer Registry also reported a significant increase in thyroid cancer incidence among both males and females during the last three decades [13,14].

Thyroid tumors typically present as painless thyroid nodules, usually in a clinically euthyroid patient. The nodule may have been detected by the patient himself or herself, picked up during clinical examination, or on ultrasound of the neck as an incidental finding [14]. The majority of nodules are benign, and the reported malignancy rates vary between 3.5 and 29 % [15,16].

Thyroid cancer usually presents as a solitary thyroid nodule, and less than 1 % of these cases can come with unusual presentations [17].

Otalgia is an extremely rare first presentation for thyroid cancer; however, some previous studies reported several causes of referred otalgia in the head and neck region; according to Kim et al. in 2007, dental pathologies were the most common etiology, accounting for 50 % of referred otalgia [18]. Another study by Mulwafu et al. stated that the incidence was found to be 33 % in cases of carcinoma of the base of the tongue [19]. Bell's palsy was also reported as a cause of referred otalgia where the ear examination is normal [20].

The pathologies of cervical vertebrae, styloid process, temporomandibular joint, metastases to the pharynx, and nasopharyngeal carcinoma have also been identified as leading causes of referred otalgia [[21], [22], [23], [24]].

Thyroid inflammation, including acute and subacute thyroiditis, can be the underlying cause of the pain referred to the ear and the angle of the mandible [25].

Arnold's nerve, a branch of the vagus nerve, provides sensation to the posterior and inferior aspects of the external auditory canal, lateral surface of the tympanic membrane, and concha. Thyroid diseases, laryngeal lesions, and gastroesophageal reflux can be presented with referred otalgia via the vagus cranial nerve [26].

This article is the first in a series of five cases. All of them are thyroid cancers, treated with surgery, and detected by otalgia.

4. Conclusion

In the presence of deep-seated ear pain in case of thyroid nodule and absence of any ear lesion after careful examination, the clinician may suspect malignant thyroid nodule; this is a possible site of origin of the earache. However still a very rare etiology, we report five cases of thyroid carcinoma, variant types, presented by referred otalgia.

Consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal up on request.

Ethical approval

Ethics approval is not required for case reports or case series deemed not to constitute research according to our institution's Research Ethics committee. All case reports and series are exempted from ethical approval and informed consents are essential. Informed consents are provided for all 5 patients of this study.

Funding

None.

Author contribution

R.A. Alzahrani: Study concept or design, data collection, data interpretation, writing the paper, revision and validation.

Guarantor

RA Alzahrani.

Research registration number

N/A.

Conflict of interest statement

None.