Effectiveness of the thyroid scan in evaluation of the solitary thyroid nodule.

Solitary, palpable thyroid nodules are common, but only a small percentage are malignant. It is important to evaluate these nodules in a cost-efficient manner that avoids missing a cancer. Historically, radioisotope imaging has played a major role in the workup of thyroid nodules; however, with the advent of fine needle aspiration biopsy (FNAB), this role has become less clear. From 1974 to 1994, 770 patients with a solitary nodule underwent thyroidectomy. Preoperatively, 471 had thyroid scans, and 149 had FNAB. The incidence of carcinoma in nodules excised on the basis of thyroid scan was 23 per cent, whereas the incidence of carcinoma was 37 per cent when FNAB was used (P = 0.003). Fine needle aspiration was a significantly better predictor of malignancy than thyroid scan and resulted in a smaller proportion of excisions for benign nodules. Thyroid scan provided little additional information in those patients who underwent FNAB. Because thyroid scans add little in determining which nodules require surgical excision, they should no longer be a routine part of the evaluation of a solitary thyroid nodule.

Cryosurgery of breast cancer.

OBJECTIVE: To determine the feasibility and efficacy of cryosurgery of breast cancer. DESIGN: In phase 1, carcinogen-induced mammary adenocarcinomas in 13 Sprague-Dawley rats were treated by cryosurgery and were then examined for histopathologic change. In phase 2, transplantable mammary adenocarcinomas in 50 DBA/IJ mice were treated by cryosurgery to determine the effect of varying tumor temperatures, and duration and number of freeze-thaw cycles on tumor viability. In phase 3, 2- to 3-cm ultrasound-monitored cryolesions were formed in the breasts of 4 dogs and 4 sheep. These animals were followed up for procedure-related complications; the histopathologic necrosis of the cryolesions were correlated with the ultrasound images. Based on the results of these experiments, ultrasound-guided cryosurgery of breast cancer was initiated in a human clinical trial. RESULTS: In phase 1, a single, short-term (< 7 minutes) freeze killed only tumors smaller than 1.5 cm in diameter, despite an apparent decrease to -40 degrees C at the periphery of each tumor. In phase 2, varying the peripheral tumor temperature to as low as -70 degrees C, using a single, short-term (< 7 minutes) freeze did not alter the results from phase 1. If the ice ball fully encompassed the tumor, however, maintaining it for at least 15 minutes achieved 100% tumor kill independent of tumor size. In phase 3, creation of a reproducible ultrasound-monitored cryolesion was facilitated when 2 freeze-thaw cycles were performed. No procedure-related complications were noted. In the human trial, 2 invasive lobular carcinomas from 1 patient were treated by cryosurgery and were negative for persistent tumor by core needle biopsy performed 4 and 12 weeks after a well-tolerated procedure. CONCLUSIONS: In situ breast cryosurgery has been proved to be feasible and efficacious in small and large animal studies and has been successfully performed in 1 patient with breast cancer. The results of this study suggest that ultrasound-guided cryosurgery of breast cancer warrants further investigation.

User of fine-needle aspiration biopsy and frozen section in the management of the solitary thyroid nodule.

BACKGROUND: This study evaluates the indication for frozen section (FSx) in the management of the solitary thyroid nodule given the increasing use of fine-needle aspiration biopsy (FNAB). METHODS: The charts of 561 patients who underwent thyroidectomy for a solitary nodule were reviewed. Each patient underwent either FNAB, FSx, or both. Results were compared to the final diagnosis to evaluate their effectiveness in predicting malignancy. RESULTS: The sensitivity and specificity for FNAB alone (162 patients) were 86% and 91%, respectively, and for FSx (494 patients) 79% and 99%, respectively. The routine use of FSx with diagnostic FNABs did not improve the accuracy over either test alone. Sensitivity, specificity, and accuracy were essentially unchanged when the use of FSx was limited to just atypical FNAB but dropped significantly when FSx was not used. CONCLUSIONS: When results of FNAB and FSx are interpreted as benign or malignant, both are highly accurate predictors of malignancy. Routine use of FSx and FNAB does not improve the sensitivity or specificity in the detection of malignancy over that of either examination alone. FSx proved useful in determining the extent of operation only when results of the FNAB were atypical.