Cytologic evaluation of surgical irrigation fluid following resection of head and neck squamous cell carcinoma

Introduction: Historically, squamous cells exfoliated from head and neck ca rcinoma resection have been implicated in locoregional recurrence, but ther e have been few studies demonstrating the presence of these cells. This stu dy was designed to evaluate the presence of exfoliated malignant cells in s urgical irrigation fluid collected during head and neck cancer resection. Methods: Thirty patients undergoing surgery for biopsy-proven squamous cell carcinoma had their surgical sites irrigated with 1000 cc of normal saline . Surgical gloves and instruments were also washed. These samples were prep ared and stained using standard squamous cell cytologic stains. All cases w ere reviewed by one cytopathologist. Results: Eighteen patients (60%) had positive or suspicious cytology detect ed in at least one of the surgical samples. In patients with TO and T1 tumo urs, ail surgical samples were negative. Positive or suspicious cytology wa s detected in the primary site and glove and instrument irrigation in 40% o f patients with T2 rumours, 42% of patients with T3 rumours, and 50% of pat ients with T4 rumours. This was statistically significant (p < .05). Positi ve or suspicious cytology was detected in the neck and glove and instrument irrigation in 29% of patients with an NO neck, 31% of patients with an N1 neck, 39% of patients with an N2 neck, and 100% of patients with an N3 neck . Five of seven patients (71%) with previous radiation therapy had positive or suspicious cytology in at least one of the surgical samples. Conclusions: Higher tumour and nodal staging and a previous history of radi ation therapy are associated with an increased incidence of positive or sus picious cytology in surgical irrigation fluid. These findings have implicat ions for surgical protocols.