A 31-year-old male patient presented to the emergency department (ED) with a 6-week history of left-sided lateral neck pain, accompanied by a minor localized swelling. He denied throat aches, dyspnea, fever, weight loss, or other constitutional symptoms.
Three weeks after the appearance of the neck pain, the patient contracted a mild coronavirus disease 2019 (COVID-19), manifesting with anosmia and ageusia. The latter symptoms improved within several days, but the neck pain persisted throughout the whole period. The patient's past medical history was otherwise unremarkable.
On physical examination, prominent tenderness was noted over the left common carotid (LCC) artery, with subtle swelling. Upper extremity pulses were symmetrical. While blood counts, serum creatinine, and erythrocyte sedimentation rate were within normal limits (WNLs), C-reactive protein (CRP) was mildly elevated (Table 1). Doppler ultrasound (US) displayed evident LCC wall thickening, without luminal stenosis (Figure 1(a)). Head and neck computed tomography angiography (CTA) scan, however, showed no vasculitic lesions (Figure 1(b)). In light of the laboratory and CTA results, the patient was discharged, with the diagnosis of vasculitis being erroneously deferred.
A repeat US performed two days later, per the radiologist's insistence, confirmed significant LCC wall thickening, thus, the patient was again referred to the ED for further evaluation. This time, he was hospitalized, and a head and neck magnetic resonance imaging (MRI) scan was completed, showing prominent LCC wall thickening, compatible with vasculitis (Figure 1(c)). Antinuclear antibodies (ANAs), anti-neutrophil cytoplasmic antibodies (ANCAs), and immunoglobulin levels, including immunoglobulin G4 (IgG4), were all unremarkable (Table 1). Serologies for syphilis and human immunodeficiency virus (HIV) were negative. In light of these findings, positron emission tomography (PET)-CT was carried out. While no active vasculitis was observed, hypermetabolic mediastinal and hilar lymphadenopathy was seen (Figure 1(d)). As such, bronchoscopy with endobronchial US transbronchial needle aspiration (EBUS-TBNA) was performed, and mediastinal lymph nodes (LNs) were biopsied. Pathology results demonstrated noncaseating granulomas (Figure 2), with negative acid fast and silver stains. Immunohistochemical staining for IgG4 was also negative. Further evaluations, including electrocardiography, transthoracic echocardiography, ophthalmologic check-up, pulmonary function tests, urinalysis, and urinary calcium levels, were all unremarkable. Angiotensin-converting enzyme (ACE) levels in blood were elevated, however. The typical radiologic and pathological features led to the diagnosis of sarcoidosis.
Prednisone, 40 mg, was started, leading to immediate resolution of carotidynia. Repeat neck US, within 6 weeks of therapy, revealed improvement of the sonographic findings (Figure 3). Likewise, a chest CT scan, performed within 4 months, showed diminution of the known hilar and mediastinal lymphadenopathy.