Transient Hyperattenuating Oral Pseudolesion Mimicking Sialolithiasis Incidentally Detected on Chest Computed Tomography

Introduction

Head and neck computed tomography (CT) occasionally depicts comestible intraoral foreign bodies (IOFBs), such as candies or chewing gum, which can mimic calcified lesions, including sialoliths or mucosal calcifications. These pseudolesions can lead to diagnostic confusion, unnecessary follow-up imaging, and patient anxiety. Prior studies emphasize recognizing IOFBs based on their CT characteristics and performing oral cavity inspection before imaging [1,2]. Familiarity with the floor-of-mouth anatomy, including the course of Wharton’s duct relative to the sublingual and submandibular spaces, is essential when evaluating anterior oral hyperattenuating foci [3]. Edible intraoral foreign bodies are occasionally encountered on CT and can be mistaken for calcified pathology because their attenuation can overlap that of true calcifications. Prior reports have described typical CT appearances of IOFBs and emphasized pre-scan oral cavity inspection as a simple strategy to reduce false-positive interpretations [1,2].

Case Report

A previously healthy 35-year-old woman presented with a 3-day history of pharyngeal discomfort and dry cough. She denied fever, odynophagia, meal-related pain, and drooling. Medical, medication, and smoking histories were unremarkable. Physical examination showed no oral ulceration or swelling.

The initial study was a non-contrast chest CT for cough evaluation. At the superior edge of the field of view, partially including the lower neck and anterior floor of the mouth, an incidentally noted, well-defined hyperattenuating focus was identified adjacent to the right sublingual gland (maximum diameter ~10 mm; mean attenuation ~400 Hounsfield units) (Figure 1A). Because the chest CT only partially covered the neck, ductal continuity with Wharton’s duct, ductal dilation, and perilesional inflammatory changes could not be assessed with confidence.

The initial differential diagnosis included a distal Wharton’s duct sialolith. An intraoral examination was performed immediately after the scan by a radiologist (H.T.); however, no obvious abnormalities or sialolith were identified within the visible field. Because the patient’s symptoms were mild and she had scheduling constraints, the follow-up study was performed 7 days later. A dedicated non-contrast neck CT obtained under identical technical parameters demonstrated complete resolution of the hyperattenuating focus (Figure 1B). On further questioning, the patient recalled having a cough lozenge in her mouth during the initial (chest) scan. Her symptoms resolved spontaneously, and no salivary-gland–related concerns were reported thereafter.

To support reproducibility, we performed an ex vivo CT scan of a commercially available cough lozenge that was nearly identical to the one reportedly used by the patient. The lozenge was placed in a small plastic container and scanned in air using the same non-contrast protocol and reconstruction settings as the patient’s CT. The lozenge appeared as a well-circumscribed hyperattenuating focus, with a mean attenuation of approximately 390 Hounsfield units (range 360–430), closely resembling the pseudolesion observed on the initial scan (Figure 2A, 2B).

Discussion

Comestible IOFBs such as hard candies and gum are consistently hyperattenuating on CT and can be mistaken for calcified pathology, especially in the anterior floor of the mouth, where the distal Wharton’s duct courses. A previous report defined characteristic appearances and stressed that attenuation often overlaps that of calcified lesions; therefore, density alone is insufficient for discrimination. Short-interval reversibility after oral cavity clearance is a decisive clue [1]. A recent case report similarly documented a cough lozenge visualized during CT, where recognition and removal averted unnecessary testing [2].

By contrast, true sialolithiasis usually involves the submandibular gland and Wharton’s duct and is frequently accompanied by meal-related pain/swelling and ductal dilation. When imaging is required, CT performs better for stone detection compared with endoscopic or surgical reference standards [4]. In our patient, the absence of ductal dilation and anatomic ductal continuity, together with complete resolution after oral cavity clearance, strongly argued against a persistent calculus.

An additional practical point in this report is that the hyperattenuating focus was captured incidentally at the cranial edge of a chest CT. In this case, CT was used because the hyperattenuating focus was incidentally detected on a chest CT obtained for cough evaluation. While ultrasound is useful for evaluating salivary stones, a short-interval dedicated neck CT was performed to confirm interval resolution and to match the initial imaging modality for direct comparison. Non-dedicated acquisitions can preclude confident assessment of ductal continuity and secondary signs. When an anterior floor-of-mouth hyperattenuating focus is encountered, particularly at the edge of a non-dedicated acquisition, practical safeguards include routine pre-scan oral cavity clearance, structured assessment of ductal continuity/dilation with clinical correlation, and limited repeat neck CT after clearance when uncertainty persists [1,3].

Several caveats should be noted. Same-day rescanning was not performed, and the initial hyperattenuating focus was captured at the cranial edge of a chest CT, which limited assessment of ductal continuity and secondary signs. Ultrasound correlation was not obtained; however, the complete interval resolution on dedicated neck CT, together with ex vivo replication, supports the interpretation as an edible IOFB.

Conclusions

An intraoral hyperattenuating focus adjacent to the right sublingual gland completely resolved on short-interval follow-up CT after oral cavity clearance, confirming an edible IOFB (cough lozenge) mimicking a distal Wharton’s duct stone. Careful attention to anatomic plausibility, secondary signs, and reversibility, supplemented by routine pre-scan oral cavity checks, can prevent misdiagnosis and avoid redundant testing.