A novel classification of carotid body tumors

Preoperative radiological features in predicting complications of carotid body tumor resection

OBJECTIVE

Carotid body tumors (CBTs) are rare neoplasms that pose significant surgical challenges. This study aims to evaluate the predictive utility of preoperative radiological characteristics on postoperative complications in patients undergoing CBT resection at a tertiary care center.

METHODS

A retrospective analysis was conducted on 106 patients who underwent CBT resection between 2003 and 2023. Patient demographics, tumor characteristics, and operative details were collected. The primary outcomes were an estimated blood loss (EBL) >250 mL and cranial nerve (CN) injury. Logistic regression models were used to identify significant preoperative radiological predictors, including Shamblin grade, Peking Union Medical College Hospital (PUMCH) grade, tumor distance to the base of the skull (DTBOS), and tumor volume.

RESULTS

One hundred six patients were included. Higher Shamblin and PUMCH grades were significantly associated with increased EBL and CN injury. Specifically, the Shamblin grade alone predicted an EBL >250 mL with a McFadden R2 value of 0.14, which slightly decreased to 0.13 when DTBOS and tumor volume were added. For CN injury, the Shamblin grade alone had an R2 of 0.16, which significantly improved to 0.27 with the addition of DTBOS and further to 0.29 with tumor volume. The PUMCH grade alone predicted an EBL >250 mL with an R2 value of 0.08, which did not significantly change with the addition of DTBOS and tumor volume. For CN injury, the PUMCH grade alone had an R2 of 0.14, improving to 0.21 with DTBOS and to 0.22 with tumor volume. Furthermore, a 1-cm decrease in DTBOS significantly increased the odds of requiring a blood transfusion (odds ratio, 2.26; 95% confidence interval, 1.28-4.01; P = .0051) and the risk of CN injury (odds ratio, 3.65; 95% confidence interval, 1.98-6.73; P < .0001).

CONCLUSIONS

This study identified novel preoperative radiological predictors that enhance the predictive accuracy of standard classification systems, offering valuable insights for preoperative planning. Although the Shamblin and PUMCH classifications are useful tools on their own, our findings demonstrate that incorporating additional radiological features, such as DTBOS and tumor volume, can substantially increase their predictive utility. Surgeons are encouraged to incorporate multiple preoperative radiological variables alongside traditional classification systems to better assess the risk of postoperative complications. Further research with larger, multi-institutional cohorts are necessary to validate these findings and refine predictive models.

A 37-year-old female with a carotid body tumor (paraganglioma): A rare case report from Syria

INTRODUCTION AND IMPORTANCE

This case study presents the clinical details of a 37-year-old woman who presented with an asymptomatic swelling in the right supraclavicular region, ultimately diagnosed as a carotid body tumor (CBT).

CASE PRESENTATION

The patient's medical background, which included her brother's CBT, prompted further investigation. Upon clinical examination and imaging studies, a tissue mass surrounding the right internal carotid artery was identified. Subsequent surgical resection of the tumor was performed, and histological analysis confirmed a neoplastic proliferation consistent with paraganglioma.

CLINICAL DISCUSSION

This case highlights the significance of taking into account familial history and conducting comprehensive diagnostic assessments for patients exhibiting similar symptoms. The successful multidisciplinary management of this rare tumor underscores the importance of early detection and appropriate therapeutic interventions.

CONCLUSION

This report offers valuable insights into the clinical presentation, diagnostic process, and treatment of CBTs, emphasizing the necessity for a comprehensive approach to managing this uncommon neoplasm.

Single-cell transcriptome analysis reveals tumoral microenvironment heterogenicity and hypervascularization in human carotid body tumor

Carotid body tumor (CBT) is a rare neck tumor located at the adventitia of the common carotid artery bifurcation. The prominent pathological features of CBT are high vascularization and abnormal proliferation. However, single-cell transcriptome analysis of the microenvironment composition and molecular complexity in CBT has yet to be performed. In this study, we performed single-cell RNA sequencing (scRNA-seq) analysis on human CBT to define the cells that contribute to hypervascularization and chronic hyperplasia. Unbiased clustering analysis of transcriptional profiles identified 16 distinct cell populations including endothelial cells (ECs), smooth muscle cells (SMCs), neuron cells, macrophage cells, neutrophil cells, and T cells. Within the ECs population, we defined subsets with angiogenic capacity plus clear signs of later endothelial progenitor cells (EPCs) to normal ECs. Two populations of macrophages were detectable in CBT, macrophage1 showed enrichment in hypoxia-inducible factor-1 (HIF-1) and as well as an early EPCs cell-like population expressing CD14 and vascular endothelial growth factor. In addition to HIF-1-related transcriptional protein expression, macrophages1 also display a neovasculogenesis-promoting phenotype. SMCs included three populations showing platelet-derived growth factor receptor beta and vimentin expression, indicative of a cancer-associated fibroblast phenotype. Finally, we identified three types of neuronal cells, including chief cells and sustentacular cells, and elucidated their distinct roles in the pathogenesis of CBT and abnormal proliferation of tumors. Overall, our study provided the first comprehensive characterization of the transcriptional landscape of CBT at scRNA-seq profiles, providing novel insights into the mechanisms underlying its formation.

Midline Mandibulotomy for large Carotid body tumors: A valuable approach

In the present case, a 41-year-old male patient had reported a large swelling on the right side of his neck that had been radiographically diagnosed as a carotid body tumor. The tumor extended toward the right thyroid lobe, deep to the parapharyngeal space and cranially to the base of the skull. The clinical and medical imaging findings confirmed the diagnosis. Because of the large size of the tumor (50 mm × 48 mm × 85 mm), extent of involvement, and hypervascularity, surgical excision by midline mandibulotomy was chosen as the treatment approach. Midline mandibulotomy is a very good approach for large tumors with extensive involvement of the surrounding tissues, especially tumors with great medial and cephalic extension.

Application of the shear wave elastography in the assessment of carotid body tumors: A preliminary study

Objectives

To evaluate the elasticity of carotid body tumors (CBTs) by two-dimensional shear wave elastography (SWE).

Methods

22 pathologically or clinically confirmed CBTs in 16 patients were scanned by SWE. The maximum elasticity value (Emax) and its standard deviation (SDmax) in kPa and m/s for CBTs were obtained by placing a round ROI (2-3 mm) on the stiffest region of the CBTs. Elasticity value was compared between hard and soft groups at manual palpation, benign and malignant groups and among three Shamblin types. The area under the receiver operating characteristic curve (AUC) analysis was performed to evaluate the performance of SWE in the malignancy prediction of CBTs. Sensitivity, specificity and accuracy were calculated. The cut-off value was obtained by using the Youden index.

Results

There were 19 benign CBTs and 3 malignant CBTs. Emax (kPa and m/s) and SDmax (kPa) were significantly higher in the hard group than in the soft group at manual palpation (P<0.05); The distribution of Emax in kPa and m/s and SDmax in kPa were different in the three Shamblin types (P<0.05), Emax (kPa and m/s)increased from shambling I to Shambling II and Shambling III; Emax (kPa and m/s) were significantly higher in the malignant CBTs than in the benign ones (P<0.05). Emax in kPa and m/s had the similar AUC value (AUC=0.947, P=1.0000) for the prediction of malignant CBTs. Emax in kPa with the cut-off 124.9kPa showed a sensitivity of 100.0%, specificity of 94.7%, and an accuracy of 95.5% (Z=8.500, P<0.0001); Emax in m/s with the cut-off 5.9m/s showed a sensitivity of 100.0%, specificity of 89.5% and an accuracy of 90.9% for the prediction of malignant CBTs (Z=9.143, P<0.0001).

Conclusions

Quantitative analysis of SWE obtained the good performance in the elasticity assessment of CBTs.