Patient information: a young 30-year-old female complained of right-sided neck swelling for 4 years and intermittent pain over swelling for 4-5 months. No history of fever, cough, weight loss, or anorexia was present. No history of movement of swelling with deglutition was noted. No history of swelling on the left side of the neck, bilateral axillary region, ptosis, loss of sweating, hoarseness of voice, and syncopal attacks was present. The patient was not a known case of tuberculosis, hypertension, or diabetes mellitus.
Clinical findings: on local examination, a relatively well-defined swelling of approximate size 2 x 2 cm is noted at the anteromedial aspect of the sternocleidomastoid (SCM) muscle, just below the angle of the mandible on the right side of the neck (Figure 1). The swelling was firm-hard in consistency, slightly tender, slightly pulsatile, and slightly ballotable on side-to-side movement. No evidence of a local rise in temperature was noted. Bilateral carotid arteries were palpable. On general examination, she was stable and afebrile with a pulse rate of 90 beats per minute and blood pressure (BP) of 120/80 mmHg. Breast examination and systemic examination were within normal limits. Laboratory investigations such as complete blood count (CBC), thyroid function test (TFT), kidney function test (KFT), and liver function test (LFT) were within normal limits.
Diagnostic assessment: the patient has been further advised a neck ultrasound. On B mode ultrasonography neck, a well-defined ovoid homogenously isoechoic lesion of size 2.1 x 2.2 cm is noted just above the bifurcation of the right common carotid artery (CCA) causing splaying of the external carotid artery (ECA) and internal carotid artery (ICA). No evidence of calcification was noted within this lesion. No evidence of adjacent inflammatory changes is noted (Figure 2). On color Doppler, minimal vascularity is noted within this lesion (Figure 3). No evidence of lymph nodes is noted in the bilateral cervical region. Bilateral CCA S, bilateral ICA S, and bilateral ECA S show normal course and caliber with normal grey scale features. Duplex Doppler study shows normal laminar flow in bilateral CCA, ECA, and ICA with normal flow velocities and waveform patterns. A diagnosis of the well-defined isoechoic lesion at the bifurcation of the right CCA is likely a CBT was made.
The patient was advised contrast-enhanced computed tomography (CECT) of the neck for further confirmation. On plain computed tomography (CT) sagittal (sag) section, an ill-defined soft tissue density mass lesion is noted on the right side of the neck anterior to the SCM muscle inferior to the angle of the mandible at the level of the hyoid bone extending superiorly up to suprahyoid space at C4-C6 vertebral level. No evidence of calcification was noted within (Figure 4). On the post-contrast study axial section, the bilobed mass lesion is noted in the carotid sheath on the right side of the neck at the bifurcation of the right CCA causing splaying of the ICA and ECA called Lyre s sign. It shows intense homogeneous enhancement. Multiple thin tortuous channels are noted around this lesion (Figure 5, Figure 6). According to the Shamblin group system, the tumor's circumferential angle of contact with ICA is a group I (<180 degrees of encasement).
Diagnosis: a diagnosis of the well-defined homogeneously enhancing lesion at the bifurcation of the right CCA suggestive of carotid body tumor was made.
Therapeutic interventions: the patient underwent surgical resection of a neck tumor. Post-operative image showing bilobed mass lesion. On histopathological examination, the definitive diagnosis came as carotid body paraganglioma.
Follow-up and outcome of interventions: the patient returned to the clinic for follow-up but the further visits were inconclusive.
Patient perspective: a patient was happy after receiving successful treatment.
Informed consent: informed written consent was given by the patient.