BackgroundCarbon nanoparticles (CNs) have been widely used in the protection of the parathyroid gland and act as a tracer agent in central lymph node dissection. However, the right time for CN injection has not been well illustrated in the transoral endoscopic thyroidectomy vestibular approach (TOETVA). The purpose of this study was to evaluate the safety and feasibility of the preoperative injection of CNs in TOETVA for papillary thyroid cancer.MethodsFrom October 2021 to October 2022, a total of 53 consecutive patients with PTC were retrospectively analyzed. All patients underwent unilateral thyroidectomy via the TOETVA. The patients were divided into the preoperative group (n = 28) and the intraoperative group (n = 25) according to CN injection time. In the preoperative group, 0.2 ml of CNs were injected into the thyroid lobules with malignant nodules 1 h before surgery. The numbers of total central lymph node (CLN) and metastatic central lymph node (CLNM), parathyroid autotransplantation, accidental removal of the parathyroid, and the parathyroid hormone level were recorded and analyzed.ResultsThe leakage of CNs happened more frequently in the intraoperative group than in the preoperative group (P = 0.002). The mean number of retrieved CLN and CLNM was similar in the preoperative group and the intraoperative group. In parathyroid protection, more parathyroid was discovered in the preoperative group than in the intraoperative group (1.57 ± 0.54 vs. 1.47 ± 0.50, P = 0.002), but less parathyroid autotransplantation (P = 0.004) and accidental removal of the parathyroid (P = 0.036) were discovered in the preoperative group. However, the PTH level between the two groups was similar after the first day and the first month.ConclusionThe preoperative injection of CNs is a safe and effective method to protect the parathyroid glands (PGs) in patients with PTC undergoing TOETVA. However, the value of preoperative injection of CNs in TOETVA for central lymph node dissection needs to be further studied.

Solitary fibrous tumors (SFTs), which were first identified in the pleura and later at multiple anatomical locations, are rare mesenchymal neoplasms. The characteristics of SFTs include well-circumscribed margins, intense vascularity and a relatively indolent clinical course. SFTs originating from the breast are rare. To the best of our knowledge, only 33 cases of breast SFTs, including five malignant tumors, have been reported to date. In the present study, a rare case of complete resection of a giant malignant SFT is reported. A 48-year-old female patient who visited Weifang People's Hospital (Weifang, China) had a 2-year history of a right palpable breast lesion. The patient reported no other symptoms, such as skin changes or nipple discharge. An ultrasound examination revealed a giant, well-circumscribed, heterogeneous and hypoechoic lesion with central and peripheral blood flow. Owing to the large size of the lesion, mammography and magnetic resonance imaging were not feasible. Core needle biology showed that the lesion was a malignant spindle cell tumor. Following this, mastectomy and sentinel lymph node biopsy were performed. The sentinel lymph nodes exhibited metastasis. A definitive diagnosis of malignant SFT was made by microscopic examination with immunohistochemistry. The treatment strategy for benign breast SFTs should be complete surgical excision, whereas for malignant SFTs, it should include radical resection along with radiotherapy and chemotherapy. Owing to the indolent nature and late recurrence and metastasis of malignant breast SFTs, regular patient follow-up for a longer duration is essential.