CASE 934: SOFT TISSUE SEEDING MASSES in SUBCLAVIAN and PARASTERNAL, Dr PHAN THANH HẢI, Dr PHẠM THI THANH XUÂN, MEDIC MEDICAL CENTER, HCMC, VIETNAM.

 A 41-year-old female with palpable masses in the right subclavian and right parasternal regions 

 Medical history: 11 years ago, she underwent endoscopic right thyroidectomy via axillary approach due to a benign thyroid tumor.

For about a year now, the patient has noticed two lumps in the right subclavian and right parasternal regions. The lump are painless, and the patient is unsure whether it has increased in size.

Biopsy result of subclavian mass is benign thyroid tissue.

 Result of parasternal mass is thyroid tissue.

DISCUSSIONS 

Always thoroughly investigate the surgical history: when detecting nodular or mass-like lesions in the soft tissue of the neck, chest wall, or armpit, the first question to ask is: Does the patient have a history of endoscopic or robotic thyroidectomy? And compare the location of these subcutaneous masses with the location of the endoscopic port and the dissection tunnel. Disseminated nodules may have images and different sizes.

The common characteristic is that it lies along the surgical incision and the resulting cuts.

The lesions are isolated masses with relatively well-defined or irregular borders, hypoechoic or mixed cystic in appearance, located entirely within the subcutaneous soft tissue or muscle tissue along the surgical incision, with microvascularity similar to thyroid tissue signaling. BENIGN THYROID ARE STILL CONTAINS CELL DELETIONS.

Ultrasound characteristics of seeding mass:

Nodules along the endoscopic port or surgical incision may appear as hypoechoic or heterogeneous areas. Increased vascularity within the nodules increases suggestive of malignancy. Careful evaluation of size, shape, borders, echogenicity (hypoechoic is more concerning than isochoric or hyperechoic), and the presence of calcification is necessary to differentiate benign from malignant lesions. Nodules vary in size, but those larger than 6 mm should be considered cautiously, especially when they exhibit features suggestive of malignancy.