Case 7 -

Papillary Hyperplastic Nodule Zubair W. Baloch

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35-year old woman with 3.0 cm right thyroid nodule. The ultrasound examination showed a hypoechoic solid and cystic thyroid nodule with few calcification and increased vascularity. Case 7 - Figure 1 Low power of Diff-Quik® stained air-dried smear showing follicular cells arranged in loosely cohesive papillary fragment and small follicular groups. Case 7 - Figure 2 Medium power of Diff-Quik® stained air-dried smear a monotonous population of follicular cells arranged in cohesive papillary group. Case 7 - Figure 3 High power showing follicular cells with ample oncocytic cytoplasm and round to oval nuclei. Case 7 - Figure 4 Papanicolaou stained smear showing a papillary group with spindle cell proliferation. Case 7 - Figure 5 Papanicolaou stained smear showing oncocytic cells (medium power) with round to oval nuclei with prominent nucleoli, intranuclear grooves and small intranuclear inclusions (high power). Case 7 - Figure 6 Papanicolaou stained smear showing oncocytic cells (medium power) with round to oval nuclei with prominent nucleoli, intranuclear grooves and small intranuclear inclusions (high power). Case 7 - Figure 7 Papanicolaou stained smear showing oncocytic cells (medium power) with round to oval nuclei with prominent nucleoli, intranuclear grooves and small intranuclear inclusions (high power). Diagnosis: Papillary Hyperplastic nodule Papillary hyperplastic nodules are frequent in children and teenagers, however, can be seen as part of multinodualr goiter in older patients. These nodules can be hyper functioning on radionuclide scan. Grossly, these lesions are encapsulated and often demonstrate central cystification with the tips of the papillae pointing to the center of the cyst. Though most of these nodules lack nuclear features of papillary carcinoma, in some cases, especially the ones with oncocytic cells reveal intranuclear grooves and poorly formed nuclear holes. However, the cells are round in shape with prominent nucleoli and even chromatin pattern. In-spite of these changes these lesions can be diagnosed as benign on the basis of structure of papillae and nuclear cytology. Immunostains for CK-19, HBME-1 and galectin-3 are helpful in differentiating between benign and malignant papillary lesions of thyroid. The FNA specimens of solitary papillary hyperplastic nodules demonstrate Cellular smears Transgressing vessels Papillary clusters Nuclear atypia and pleomorphism, presence of intranuclear grooves, multinucleated giant cells, and cell with vacuolated cytoplasm. In view of these features, some of these cases could be misclassified as suspicious or consistent with papillary carcinoma. The cytologic features that appeared to be useful in differentiating solitary papillary hyperplastic nodules from papillary carcinoma included flame cell change, watery or inspissated colloid, short non-branching papillae and lack of well-formed intranuclear inclusions. References: Vickery AL, Jr. Thyroid papillary carcinoma. Pathological and philosophical controversies. Am J Surg Pathol. 1983;7:797-807. Casey MB, Lohse CM, Lloyd RV. Distinction between papillary thyroid hyperplasia and papillary thyroid carcinoma by immunohistochemical staining for cytokeratin 19, galectin-3, and HBME-1. Endocr Pathol. 2003;14:55-60. Rosai, J, Carcangui ML, DeLellis RA, Tumors of The Thyroid Gland. Atlas of Tumor Pathology, ed. J. Rosai and L.E. Sobin. Vol. 3rd Series, Fascicle 5. Washington, DC: Armed Forces Institute of Pathology 1992. Baloch, Z,. LiVolsi VA, Pathology of the Thyroid Gland. Endocrine Pathol, ed. V.A. Livolsi , S. Asa. Philadelphia, PA: Churchill Livingston. 61-88, 2002. LiVolsi, V.A., Papillary neoplasms of the thyroid. Pathologic and prognostic features. Am J Clin Pathol: 97(3): p. 426-34, 1992. Mai KT, Ford JC, Yazdi HM, Perkins DG, Commons AS. Immunohistochemical study of papillary thyroid carcinoma and possible papillary thyroid carcinoma-related benign thyroid nodules. Pathology, Research & Practice. 2000;196:533-40. Mai KT, Landry DC, Thomas J et al. Follicular adenoma with papillary architecture: a lesion mimicking papillary thyroid carcinoma. Histopathology. 2001;39:25-32. Prasad ML, Pellegata NS, Huang Y, Nagaraja HN, Chapelle Ade L, Kloos RT. Galectin-3, fibronectin-1, CITED-1, HBME1 and cytokeratin-19 immunohistochemistry is useful for the differential diagnosis of thyroid tumors. Mod Pathol. 2005;18:48-57. Volante M, Bozzalla-Cassione F, DePompa R et al. Galectin-3 and HBME-1 expression in oncocytic cell tumors of the thyroid. Virchows Arch. 2004;445:183-8. Livolsi VA, Merino MJ. Histopathologic differential diagnosis of the thyroid. Pathology Annual. 1981;16:357-406.