Parathyroid tissue in an adult’s cervical bronchogenic cyst

Abstract

Dear Editor, Bronchogenic cysts are rare, benign, congenital lesions that occur due to aberrant tracheobronchial tree development during embryogenesis [1–3]. They usually present in childhood, in the lungs or mediastinum, while cervical cysts are infrequent [1, 2]. Neither parathyroid gland absorption by a bronchogenic cyst nor parathyroid tissue in such a lesion has been reported. An adult’s cervical bronchogenic cyst containing parathyroid tissue, incidentally found during thyroidectomy in the right superior parathyroid gland location, is presented. A 52-year-old man presented with a multinodular goitre. Thyroid function, parathormone and calcium were normal. Ultrasound demonstrated a multinodular goitre with a 3-cm dominant nodule in the left and a 4-cm dominant nodule in the right thyroid lobe; no lymphadenopathy or additional abnormal findings were identified. Fine-needle aspiration cytology of both nodules revealed follicular cells with microfollicular pattern, occasionally showing oncocytic changes and nuclear pleomorphism but no malignant changes (Thy3 according to the Classification of the Royal College of Physicians [4]). Intraoperatively, a big multinodular goitre and a cyst in the right superior parathyroid gland location, interpreted as parathyroid cyst, were identified. No lymphadenopathy was observed. Total thyroidectomy and cyst excision were performed. The other three parathyroid glands were preserved. The thyroid gland (10×8×3 cm, 87.5 g) consisted of an enlarged (8×5.5×3 cm) multinodular right and an enlarged (4.5×3×3.5 cm) nodular left lobe. The latter lobe was almost entirely replaced by a well-circumscribed, encapsulated nodule (3.5×2.4×3 cm), which consisted of follicles with microfollicular and solid architecture and, focally, Hurthle cell changes. A focus of capsular and few foci of vascular invasion were noted. No papillary pathology features were found. Ki-67 proliferative index was <1%. Minimally invasive follicular thyroid carcinoma with capsular and vascular invasion diagnosis was offered. The cyst (0.8×0.4×0.3 cm, 0.16 g) was thin-walled, unilocular. Microscopically, the inner surface was lined by ciliated, pseudostratified, cuboidal to columnar epithelium with goblet cells. The cystic wall contained smooth muscle, seromucous glands and islands of parathyroid tissue (Fig. 1). This was confirmed by immunohistochemical parathormone demonstration (Fig. 2). There was no evidence of malignancy. A diagnosis of benign bronchogenic cyst with parathyroid tissue in its wall was made. Cervical bronchogenic cysts are infrequent, usually diagnosed in children but can rarely be encountered in adults; such aberrant location could be explicable by migration of abnormal tracheobronchial tree buds during embryogenesis [1–3]. They are often asymptomatic, frequently found incidentally during radiologic evaluation or, seldom, thyroidectomy as in our patient [5]. Although rare, they should be included in the differential diagnosis of cervical masses. Characteristic histologic findings are a ciliated, respiratory-type, pseudostratified epithelial lining with smooth muscle cells, mucous glands, cartilage and fibrous connecVirchows Arch (2008) 453:307–308 DOI 10.1007/s00428-008-0655-0