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Indian Journal of Cancer, Vol. 40, No. 2, (April - June 2003) , pp. 80-81 Case Report Maxillary Mass as the Presenting Manifestation of Papillary Thyroid Carcinoma Bhansali A, Kataria RN,* Subrahmanyam KAV, Radotra BD,** Mathur SK Department of Endocrinology, *Surgery and **Pathology, Postgraduate Institute
of Medical Education
& Research, Chandigarh - 160012, India. Code Number: cn03013 ABSTRACT A case of follicular variant of papillary thyroid carcinoma presenting with a right maxillary mass is described. This is perhaps the first instance of maxillary metastasis from papillary thyroid carcinoma. Key Words : Maxillary metastasis, Papillary thyroid carcinoma. Introduction Osseous metastases occur in 3-12% of patients with differentiated follicular and papillary thyroid cancer.1,2 Of the two, a relatively higher prevalence of bone metastasis occurs in follicular (15.2%) than in papillary carcinoma (0.6%).2 Frequent sites of osseus metastases are being sternum, vertebrae, pelvis and ribs, while metastases to maxilla has not been reported earlier.1,2 We describe a patient who presented with right maxillary mass and on investigations, was diagnosed as follicular variant of papillary thyroid carcinoma with maxillary metastasis. Case Report A 60-year-old woman presented with progressively increasing painless swelling over right cheek for 3 months. On examination, she was pale and had body mass index of 17. She had swelling over right cheek that was 5 x 4 cm in size, firm, nontender arising from the maxilla with intra-oral protrusion. She did not have cervical lymphadenopathy. Her investigations showed : Hb 9 gm/dl, fasting plasma glucose 15 mmol/L and post prandial glucose 16 mmol/L and normal renal functions and calcium profile. With this glucose profile, she was referred to Endocrinology Services. On examination, she had BP 110/70 mmHg and had a 2 x 2 cm firm, mobile nodule in right lobe of the thyroid. Other systemic examinations were normal. Thyroid function tests showed serum T3 1.1 ng/ml (0.6-1.6), T4 90 ng/ml and TSH 2.6 uU/ml (0.5-5.4). Fine needle aspiration cytology (FNAC) from the thyroid nodule and from the maxillary lesion was suggestive of follicular neoplasm with positive immunostaining for thyroglobulin. Radiology revealed a lytic lesion in maxilla, mandible and 9th rib, which was confirmed by 99mTc MDP bone scan. Her blood glucose was controlled with insulin and she underwent total thyroidectomy. Histopathology of the thyroid nodule showed follicular variant of papillary thyroid carcinoma (PTC) (Figure 1a & Figure 1b) showing papillae as well as follicular pattern with nuclei having ground glass appearance and grooving. 131I whole body scan following total thyroidectomy further confirmed the lesions in maxilla, mandible and the rib and no residual thyroid tissue. She was planned for radio-iodine ablation for osseous metastasis but lost to follow-up. Discussion This case has two interesting features : (1) an atypical site of bone metastasis and (2) an uncommon subtype of papillary thyroid carcinoma (PTC) having predominant follicular histotype (follicular variant of PTC). In one of the largest available series of 45 cases of differentiated thyroid carcinoma who had bone metastases at presentation, sternum was the most frequent site, and no case of mandibular or maxillary metastases had been reported.3 However recently, mandibular metastasis with follicular thyroid carcinoma has been reported4 and our case is probably the first case of PTC with maxillary metastasis. Morphologic variants of PTC comprise 15-20% of all papillary thyroid tumors and include sclerosing type, solid variant and follicular variant.5 The follicular variant exhibits nearly exclusive follicular pattern of growth and scanty papillae with ground glass appearance of nuclei and nuclear grooving typical of PTC. In a large series of 241 patients of papillary thyroid carcinoma, only 25 (11.4%) patients had follicular variant of PTC.5 The clinical behaviour of `follicular variant' is identical to PTC except that these tumours tend to be smaller, preferentially metastasize through hematogenous route rather than through lymphatics in classical papillary thyroid cancer and have a higher incidence of lung metastasis.5 Papillary thyroid cancer with bone metastasis but without nodal involvement needs a consideration for follicular variant of papillary thyroid cancer. Our patient had a small thyroid nodule and had osseous metastasis without regional lymphnode involvement with histological diagnosis of follicular variant of papillary thyroid carcinoma. The bone metastasis are recognized by plain X-ray, CT, 99mTc MDP bone scan and 131I whole body scan following total thyroidectomy.3 The localization is useful for elective excisional surgery in solitary metastasis as this improves the outcome.2 In our patient 99mTc MDP bone scan showed maxillary, mandibular and rib metastases which was further substantiated by 131I scan after total thyroidectomy. In patients with localized bone disease (solitary metastasis), radical resection followed by radio-iodine ablation provide longer disease free interval and better quality of life.2 However, response to radio-iodine ablation alone is poor in patients with multiple osseous metastases and seldom survive 10 years after treatment.6 The poor response to radio-iodine is apparently due to the lower uptake by bone lesions.2 In our patient, because of multiple osseous lesions with good tracer uptake, 131I radio-ablation was planned but could not be contemplated. Despite the good prognosis for differentiated thyroid cancer, 10% of all patients with papillary and 20-40% with follicular carcinoma succumb to distant metastases.3 Bone metastases are associated with poor prognosis in terms of quality of life and survival as compared to lung and lymphnode metastases.1 References
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