Malignant pleural effusion from papillary thyroid carcinoma diagnosed by pleural effusion cytology: A case report

Abstract

Papillary thyroid carcinoma (PTC) is by far the most common thyroid malignancy (over 85%) of all the thyroid cancers. It has excellent prognosis and 10-year survival rate in most of the cases (95%). Most of the tumors are indolent and do not recur or metastasize after removal. However, widespread metastases to lung, skeleton, central nervous system and, occasionally, other organs may be observed. In rare instances, this disease may metastasize to the pleura and manifest as a malignant pleural effusion (MPE) and portend poor prognosis. This article reports the cytomorphologic and immunocytochemical findings of a female patient with a symptomatic pleural effusion resulting from PTC metastatic to the pleura. Pleural fluid cytology revealed abundant papillary clusters with relatively nuclear pleomorphism, intranuclear cytoplasmic inclusions and nuclear grooves, small and distinct nucleoli as well as small discrete vacuoles. Psammoma bodies were not seen. Immunocytochemical staining was positive for TGB, EMA, Ber-EP4, CK19, and negative for TTF-1. Metastasis of PTC to pleural fluid is extremely rare and diagnosing the disease by cytology is challenging and requires medical expertise as well as knowledge of clinical context and immunocytochemical staining. Additionally, a cytologic diagnosis of MPE due to PTC provides important treatment information and plays an important role in prognosis.

Pleural fluid due to papillary thyroid cancer

“…However, as this is a rare condition, standard therapy has not yet established. This case report documents our clinical experience, we present herein a patient with pleural fluid due to papillary thyroid cancer, and reviewed previously reported such cases (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19).…”

“…Massive pleural fluid caused by thyroid cancer is very rare. To our best knowledge, there have been reported only 51 cases (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). According to a review by Vassilopoulou-Sellin and Sneige at the MD Anderson Cancer Center, 10 (0.6%) had malignant pleural fluid that developed during the course of the disease among 1772 differentiated papillary thyroid cancer patients (4).…”

“…The articles detected are shown in References (Reference no. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Fifty-one patients of pleural fluid due to thyroid cancer were confirmed.…”

“…Lung metastases of thyroid cancer are those to the lung parenchyma, such metastases usually have multiple small nodules in both lungs (1,2). On the contrary, however, pleural fluid due to thyroid cancer is a rare etiology, to our knowledge, and only 51 cases have been reported (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Pleural fluid due to thyroid cancer has been reported to be less than 1% in all the patients with malignant pleural fluids (4,11).…”

“…Papillary thyroid cancer was the major histologic type of thyroid cancer with pleural effusion, and other histologic types were few (3). Thyroid cancer patients with pleural fluid, regardless of tissue type, were long-term survivors (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). In general, diagnosis of malignant fluid is established by positive pathological findings using specimens from pleural fluid (20).…”