[Frozen section doesn't reduce the number of reoperations for cancer after hemithyroidectomy]. / La biopsia intraoperatoria no reduce la tasa de reintervenciones por cáncer tras hemitiroidectomía.

UNLABELLED: FUNDAMENTALS AND OBJECTIVES: Frozen section (FS) constitutes a diagnostic procedure in patients following hemithyroidectomy. It is used to diagnose malignant lesions and to avoid reoperations. Our objective is to confirm this test as useless to rule out cancer. PATIENTS AND METHODS: Retrospective and comparative trial between two series of patients following hemithyroidectomy. G I: 179 patients operated in 1995-2002. In this period we performed systematic FS. Sensitivity (S), specificity (E) and predictive values (PPV, NPV) are analyzed. G II: 126 patients were operated between 2003-2008. Selective FS was performed (23 patients). Both groups are compared: hospital stay, number of FS, percentage of cancer, definitive biopsy and reoperations. RESULTS: Data analyzed in the first period: S: 48%, E: 100%, PPV: 100%, NPV: 90%, positive likelihood ratio>10, negative likelihood ratio 0.52. When both periods are compared no significant differences between reoperations are found. CONCLUSION: FS during hemithyroidectomy does not reduce reoperations for cancer.

[Diagnostic value of intraoperative parathyroid hormone decline in prediction of hypocalcemia after total thyroidectomy]. / Validez diagnóstica del descenso intraoperatorio de paratirina en la predicción de hipocalcemia tras tiroidectomía total.

BACKGROUND AND OBJECTIVE: Transient or definitive hypocalcemia is one of the most important complications following total thyroidectomy. Monitoring of serum calcium levels or calcium replacement in all patients are methods commonly used to avoid this problem. Our objective was to validate the intraoperative parathormone assay (PTH) as a predictive tool in these situations. PATIENTS AND METHOD: We conducted a prospective study of 46 patients undergoing total thyroidectomy. PTH levels were obtained during the anesthetic induction, 10min after the procedure and 24h after surgery. Calcium levels were obtained 24 and 48h after surgery. The predictive value of postoperatory levels of PTH and its decline respect the preoperatory levels for prediction of hypocalcemia was measured. Hypocalcemia was defined as an ionized calcium<4mg/dl (<1mmol/l). RESULTS: Of 46 patients, 13 (28.3%) developed hypocalcemia. Isolated postoperative PTH level was a poor predictor of hypocalcemia. Nevertheless, when the gradient between preoperative and postoperative levels of PTH was considered, the rate of the decline became a good predictor of hypocalcemia, with 85-90% being the most accurate cut-off point. CONCLUSIONS: The decline of PTH in the immediate postoperative period of patients undergoing total thyroidectomy is a reliable test for predicting hypocalcemia.

[Utility of frozen section in the surgical treatment of thyroid nodules]. / Utilidad de la biopsia intraoperatoria en el tratamiento quirúrgico del nódulo tiroideo.

OBJECTIVE: To present our experience of the use of frozen section (FS) in the operative management of thyroid nodules and determine the utility of this procedure when deciding the extent of thyroidectomy. PATIENTS AND METHOD: We performed a prospective and comparative study. The FS of patients who underwent surgery for thyroid nodules between 1995 and 2002 were evaluated. The results were compared with those of fine-needle aspiration cytology (FNA) and definitive biopsy. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of both FNA and FS were calculated. RESULTS: There were 469 thyroidectomies and 179 FS were performed. The results obtained for FNA and FS were, respectively: PPV: 100%/100%; NPV: 89%/90%; diagnostic accuracy: 89.5%/91%. When only "follicular hyperplasia" was included as the cytologic diagnosis, the PPV and NPV for FS were 100% and 86.7%, respectively. CONCLUSION: The diagnostic accuracy of FNAC and FS is similar. In cases of follicular hyperplasia, the sensitivity of FS is too low to rule out malignancy.

[Gastrointestinal stromal tumors. Diagnosis, prognosis and current surgical treatment. Follow-up of 18 treated patients]. / Tumores gástricos estromales. Diagnóstico, pronóstico y tratamiento quirúrgico actual. Seguimiento de 18 pacientes tratados.

INTRODUCTION: Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumors of the digestive tract and their growth is directed through the signaling of the KIT or PDFGRA genes. The objective of the present study was to describe a series of cases of GIST tumors located in the stomach. PATIENTS AND METHODS: We performed a retrospective, descriptive study of 18 patients diagnosed with gastric GIST and treated by means of gastric resection between July 1996 and June 2004. There were 12 women and six men, with a mean age of 63 years (range 33-84). In all patients, diagnosis was performed with immunohistochemical markers, such as CD34 and CD117. Investigations included endoscopy, abdominal ultrasonography, abdominal computerized axial tomography and fine-needle aspiration biopsy. RESULTS: The main symptoms were digestive hemorrhage with severe anemia in 10 patients and abdominal pain in seven. In two patients, the tumors were incidental findings during laparotomy. Four patients underwent emergency surgery and the remainder underwent elective surgery. In all patients, gastric resection of variable extension was performed, according to tumoral location. Multicentric tumors were found in two patients. All patients were CD117- and CD34-positive. There were few postoperative complications. One patient died from acute myocardial infarction (5.6%). The mean follow-up was 47.5 months (range, 12-106). One patent died due to spread of a pancreatic neoplasm and the remaining patients are alive and without tumoral recurrence (94.1%). CONCLUSIONS: Initial symptoms consist of upper gastrointestinal hemorrhage and abdominal pain. Gastroscopy and imaging techniques lead to a suspected diagnosis, which can be confirmed by immunohistochemical studies, in which the "gold standard" is positivity for CD117; CD34 (+), vimentin (+), actin (-) and protein S-100 (-) are also used. Treatment consists of tumoral resection with negative margins.