Radiological and Histopathological Assessment of Cervical Lymph Nodes in Patients With Oral and Oropharyngeal Squamous Cell Carcinoma Undergoing Neck Dissection at Kenyatta National Hospital

Abstract

STUDY BACKGROUND: Oral and oropharyngeal cancers are in the top 30 most common cancers in the world. Their five-year survival rate is about 86% with early detection and 40% if detected late. This underlies the importance of accurate and timely diagnosis of loco-regional spread to cervical lymph nodes and optimum treatment to increase prognostic outcomes. Unfortunately, cervical lymph node assessment may sometimes be inaccurate, and radiological and histopathologic evaluation may occasionally give conflicting results. BROAD OBJECTIVE: To investigate the agreement between radiological, and histopathological assessment of cervical lymph nodes in patients with oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinoma undergoing neck dissection at Kenyatta National Hospital (KNH), irrespective of the stage. METHODOLOGY: This was a cross-sectional study conducted at KNH. The study population was all patients with a histological diagnosis of OSCC and/or OPSCC scheduled for neck dissection at KNH. Convenience sampling was used to select at least thirty consecutive patients between February and June 2023. Data from reports of the radiological (preoperative) and histopathological (postoperative) assessment of cervical lymph nodes was collected and analyzed. Pattern of agreement, sensitivity and specificity of the various radiological examinations was determined. xiv RESULTS: Thirty (30) patients (16 males and 14 females) were recruited, with a mean age of 58.1+12.5 years. On radiological assessment, 21 (70%) patients had suspicious nodes, with 18 (85.7%) of them having suspicious nodes in level I and 8 (38.1%) having multi-level suspicious nodes. The most frequent clinical nodal categories were cN2b and cN1 (8; 26.7% and 7; 23.3%) respectively. On histological assessment, 16 (53.3%) patients had metastatic lymph nodes, with level I metastasis in all 16 (100%). The most frequent pathological nodal category was pN3b seen in 6 (20%) patients. There was a fair agreement between patients with clinically suspicious nodes and those with histologically confirmed nodal loco-regional spread (κ = 0.384, p < .05). The level of agreement increased to moderate when the unit of comparison was the cervical nodal level (κ = 0.512, p < .05) and further increased to substantial when the comparison was between clinical (cN) and pathological (pN) nodal categories (κ = 0.629, p < .05). CT scan had a sensitivity (true positive) of 83.3% and a specificity (true negative) of 44.4% while Magnetic Resonance Imaging (MRI) had a sensitivity (true positive) of 100% and a specificity (true negative) of 60%. CONCLUSION: The most common radiological feature of suspicious lymph nodes identified was an enlarged node of more than 9mm in diameter while the most common histopathological feature of positive lymph nodes was abnormal hilar architecture. There was a substantial agreement between radiological and histopathological assessment of cervical lymph nodes in patients with OSCC/OPSCC. MRI and CT scan had higher sensitivity (true positives) but lower specificity (true negatives). xv RECOMMENDATIONS: Magnetic Resonance Imaging (MRI) may be the better imaging for assessing loco-regional spread of OSCC/OPSCC in our setup in comparison to CT scan thus surgeons should request for more MRI. However, there is need to conduct another study with a larger sample size