PATHOLOGIST’S ROLE DURING ANATOMIC PARATHYROID EXPLORATION IN A RESOURCE POOR SETTING

Bimalka Seneviratne1, Bawantha Gamage2, Randi Mendis3 1. Department of Pathology / Cancer Research Centre, Faculty of Medical Sciences, University of Sri Jayewardenepura, Colombo, Sri Lanka 2. Department of Surgery, Faculty of Medical Sciences, University of Sri Jayewardenepura, Colombo, Sri Lanka 3. division, Lanka Hospital Diagnostics, Narahenpita, Colombo, Sri Lanka

INTRODUCTION Table 1: Gross examination findings of surgical (parathyroid) specimens Removal of parathyroid is recommended for patients suffering from Concordance (between Sensitivity Specificity surgeon & pathologist) hypercalcemia due to excess parathyroid hormone levels. There are Gross examination & 98% 98% >95% several causes for a hyper functioning parathyroid gland out of which identification parathyroid adenoma is the most common pathological entity. There is great variation in the number and location of parathyroid glands. Table 2: Sensitivity & specificity of intra-operative frozen section procedure In addition, the small size of parathyroid glands renders it difficult to Sensitivity Specificity Parathyroid abnormalities 100% 100% be correctly identified during surgery. Hence, intra-operative Non- parathyroid tissue (small lymph nodes, fat 100% 100% confirmation of parathyroid tissue makes it easier for the surgeon to globules & thyroid nodules in the vicinity) be confident of the outcome of the procedure and assure the patient of a permanent cure. Table 3: Correlation with parathyroid hormone levels (Pre and post- operative values) Pre-operative level Post- operative level Parathyroid <80 pg/ml METHODOLOGY adenoma 90-170 pg/ml (statistically significant association with the intra- A descriptive cross sectional study done in a cohort of 26 patients who n=23 operative frozen section diagnosis, p<0.05) presented with elevated total serum calcium and parathyroid hormone Parathyroid <80 pg/ml hyperplasia 90-150 pg/ml (statistically significant association with the intra- concentrations. Intra-operative frozen section diagnoses were n=3 operative frozen section diagnosis, p<0.05) correlated with routine histological studies and post-operative parathyroid hormone concentration. Table 4: Concordance of results (between intraoperative frozen section diagnosis and routine ) Concordance Discordance RESULTS Parathyroid lesions 100% (statistically significant <1% n=26 with a p value < 0.05) (statistically insignificant) The majority of patients were diagnosed as having parathyroid adenoma (88.46%). Three out of 26 patients (11.53%) had CONCLUSION parathyroid hyperplasia involving more than one gland. Sensitivity and The diagnostic accuracy of the frozen section method can be highly specificity of intra-operative frozen section diagnosis was 100%. satisfactory in the hands of experienced personnel from both medical There was a statistically significant association (p<0.05) with and technical sides. post-operative parathyroid hormone concentration and the In contrast to developed countries which have readily available intraoperative diagnosis. The concordance between the intraoperative sophisticated techniques such as sestamibi scan, single- photon findings and routine histological diagnoses was highly satisfactory. emission computed tomography, centres with limited facilities consider There were no false negative or false positive results. intraoperative frozen section diagnosis as a valuable tool for identification of the glands. Undoubtedly the cost effectiveness of this procedure in terms of human resource, infrastructure and equipment along with high accuracy will continue to have a positive impact on parathyroid surgery in a resource poor setting. Sensitivity & specificity of frozen section diagnosis and concordance of results between frozen section and subsequent histological review can be as high as 100%. There was a statistically significant association (p<0.05) with the post-operative parathyroid hormone concentration and the intra- operative diagnosis, thus reinforcing the valuable contribution of frozen sections for routine parathyroid surgery. All of these patients have been followed up during last 5 years, with serum calcium and parathyroid hormone levels and it is noteworthy to Figure 1: Intra-operative frozen Figure 2: Parathyroid adenoma (intra- mention that there is complete cure with no evidence of residual section diagnosis operative diagnosis, H&E stain at X10) disease or recurrence. n=26; Parathyroid adenoma (n=23 [88.46%]), References: Parathyroid hyperplasia (n=3 [11.53%]), 1. DuBose, J., Ragsdale, T., & Morvant, J. (2005). “Bodies so tiny”: The history of para- Parathyroid carcinoma (n=0 [0%]) thyroid surgery. Current surgery, 1(62), 91-95. doi:10.1016/j.cursur.2004.07.012 2. Lappas, D., Noussios, G., Anagnostis, P., Adamidou, F., Chatzigeorgiou, A., & Skan- dalakis, P. (2012). Location, number and morphology of parathyroid glands: results from a large anatomical series. Anatomical science international, 87(3), 160-164. doi:10.1007/s12565-012-0142-1. 3. Johnson, S. J., Sheffield, E. A., & McNicol, A. M. (2005). BEST PRACTICE NO 183: Examination of parathyroid gland specimens. Journal of clinical pathology, 58(4), 338 -342. doi:10.1136/jcp.2002.002550. 1770637. 4. Felsenfeld, A. J., Rodríguez, M., & Aguilera-Tejero, E. (2007). Dynamics of parathy- roid hormone secretion in health and secondary hyperparathyroidism. Clinical journal of the American Society of Nephrology, 2(6), 1283-1305. doi:10.2215/CJN.01520407. 5. Westra, W. H., Pritchett, D. D., & Udelsman, R. (1998). Intraoperative confirmation of parathyroid tissue during parathyroid exploration: a retrospective evaluation of the fro- zen section. The American journal of , 22(5), 538-544.

Contact: [email protected] Figure 3: Symptoms Renal calculi (n=15 [57.69%]), Abdominal pain (n=3 [11.53%]), Recurrent abortion (n=1 [3.84%]), Weakness, bone pain (n=3 [11.53%]), Incidental finding (n=4 [15.46%])