Nasreen Naz, Iqbal A Muhammad Khyani, Munir Ahmed Baloch, Murtaza Ahsan Ansari, Qamar S Khan.
Morphological Evaluation of Thyroid Nodules on Ultrasound.
Pak J Otolaryngol Jan ;30(1):03-6.

OBJECTIVE: To evaluate different morphological appearances of thyroid nodules by using high frequency 7.5 MHz ultrasound along with Doppler ultrasound to provide criteria to characterize the nodule as benign or malignant. STUDY DESIGN: Non-interventional, descriptive study. SETTING: Department of ENT and Radiology, Dow University of Health Sciences and Civil Hospital, Karachi. DURATION: January 2011 to June 2012. PATIENTS AND METHODS: All adult patients who underwent ultrasound imaging either with palpable or non palpable thyroid nodules, were included in the study. Cases of any gender, aged between 20 – 65 years, having symptoms of goiter with or without palpable lump or nodule, pain or abnormal thyroid profile were included in the study. Biopsy proven and treated cases for thyroid diseases were excluded from the study. Main outcome measures were, presence of the abnormal clinical, laboratory and ultrasonic findings. Sonographic findings that are suggestive of potential malignancy are, size, shape (taller than wider), hypoechogenecity, microcalcfication, irregular or lobulated margins, presence of septae, and solid nodule. If any one of the above criteria was present it was considered as positive case for malignancy. In all such cases cytology and post operative histopathology were advised. Statistical analysis was done for descriptive purpose. Overall sensitivity, specificity, positive and negative predictive values of thyroid nodules, frequency and percentage analysis were carried out. RESULTS: Total of 85 patients were included in the study out of which, 56 (65%) were female and 29 (34.2%) were male. Palpable lump was observed in 70 (82%) patients, while other 08 (9.4%) had non palpable symptomatic lumps. In 07 (8.2%) patients, thyroid nodules were discovered incidentally on ultrasound neck for non thyroid ultrasonic examinations. Typical single solid nodules were observed in 35 (41%) patients, and 20 (23%) patients were with typical single cystic nodules. Multiple benign solid nodules were noted in 28 (21.1%) patients and in 02(2.35%) cases diffuse goiter was observed. Potential malignant features of shape and marginal irregularity, microcalcification, hetreogenicity and type I and II abnormal flow were observed in 10 (11.7%) patients, while 20 (23%) patients had typical sonological features of malignancy, i.e., taller than wider, irregular, heterogenecity, mural solid nodules with abnormal vascularity of type III and IV. All thyroid nodules (n=85) were further assessed by cytology or post-operative histopathology. Out of 30 potentially malignant cases, 24 were true positive for malignant cells, and 06 were false positive. Out of 55 potentially non-malignant cases, 52 cases were true negative, and 03 cases were false negative. Overall Ultrasound sensitivity of morphological characteristics is estimated to be 88.8% (24/30) and specificity to be 89.6% (52/55). Negative predictive value is calculated as 94.3% (52/55) and positive predictive value of 80.6 % ( 24/30). CONCLUSION: This study reflects that high frequency ultrasound is the alternative non-invasive modality to recognize benign and malignant features of thyroid nodules by their size, shape, margins, calcifications, solid mural nodules, septae and abnormal vascularity. Morphological characterization of thyroid nodule on ultrasound substantially reduce the number of unnecessary biopsies.

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