Capillary versus aspiration techniques in fine needle biopsies

Background: Needle aspiration is currently a widely used technique in the diagnosis of unclear lesions in the head and neck region. We present a modified technique of fine needle biopsy in ENT, ''fine needle capillary technique''. The basics of this technique were developed by Zajdela and coworkers (1987) as a cytological method of fine needle biopsy in benign and malignant mammary tumors. Fine needle capillary technique does not require aspiration of cell samples via negative pressure created by a syringe. A thin 25 G needle (outer diameter 0.50 mm, length 25 mm) is introduced into the lesion with one hand. The cells are detached by the cutting edge of the needle and are conducted into the lumen by capillary force. The needle is removed and the cellular material is expelled onto a glass slide, spread, and immediately fixed. Method: In a series of 166 patients with unclear lesions in the head and neck region, we compared the fine needle capillary technique with the classic fine needle aspiration technique in each patient. Regarding quality and assessment of the cytological smear the fine needle capillary technique proved clearly superior in most of the cases. Lymph nodes, tumors of the salivary glands, thyroid glands, branchiogenic cysts, one atheroma, one lipoma, and one skin metastasis of a squamous cell carcinoma were punctured. Results: In our study fine needle capillary technique showed a very good quality of the cytological smear in 24.7% of all cases, while fine needle aspiration technique reached 12.1% only. A good quality was obtained in 51.2% with fine needle capillary technique and in 51.8% with fine needle aspiration technique, poor quality in 24.1% with fine needle capillary technique and in 36.1% with fine needle aspiration technique. Nondiagnostic cytology was obtained in 21.7% with fine needle capillary technique and in 32.5% with fine needle aspiration technique. Both techniques together showed insufficient material in 10.8%. The quality of the cytological smear in each region was always better with fine needle capillary technique than with fine needle aspiration technique except five punctures of the submandibular gland, Of 166 patients 113 (68.1%) underwent surgery, and a correlation of the cytologic report to the surgical specimen showed agreement in 95.7% with fine needle capillary technique and in 90.5% with fine needle aspiration technique. In 17.7% with fine needle capillary technique and in 25.7% with fine needle aspiration technique it was not possible to compare the cytological smear with the histological results because of poor quality of the cytological smear. In four cases (4.3%) with fine needle capillary technique the cytological diagnosis was wrong. With fine needle aspiration technique, a wrong diagnosis occured eight cases (9.5%). Conclusions: Fine needle capillary technique offers several advantages. Without aspiration trauma to cells and tissues is reduced. Less blood in the samples results in higher quality of the cytological smear. These circumstances make it easier for the pathologist to comment the cytological findings. The handling of the needle is practiced with a wrist movement and not from the shoulder Joint as in aspiration method using the Cameco syringe holder. This allows for a more sensitive puncture technique touching the lesion during sampling with the finger tips. The puncture causes less pain than the aspiration technique. Our results demonstrate that fine needle capillary technique is the better method of fine needle biopsy in the head and neck region.