Concurrent mediastinal parathyroid carcinoma and neck parathyroid adenoma: A rare presentation

c ase report Concurrent ectopic mediastinal parathyroid carcinoma and neck parathyroid adenoma: a rare presentation Konkominan mediastinal paratiroid karsinom ve boyunda paratiroid adenoma: nadir tutulum Mustafa Çalışkan1, Selvihan Beysel2,3, Muhammed Kızılgül4, Güleser Saylam5, Erman Çakal6 Department of Endocrinology and Metabolism, Düzce Atatürk State Hospital, Düzce, Turkey 1 Department of Endocrinology and Metabolism, Eskişehir State Hospital, Eskişehir, Turkey 2 Department of Medical Biology, Baskent University, Ankara, Turkey 3 Department of Endocrinology and Metabolism, Kilis State Hospital, Kilis, Turkey 4 Department of Otorhinolaryngology, Ankara Dışkapı Yıldırım Beyazıt Training and Research Hospital, Ankara, Turkey 5 Department of Endocrinology and Metabolism, Ankara Dışkapı Yıldırım Beyazıt Teaching and Research Hospital, Ankara, Turkey 6 Gönderilme Tarihi: 04.11.2017 Kabul Tarihi: 18.12.2017 Doi: 10.21601/ortadogutipdergisi.349251 Abstract While mediastinal parathyroid carcinoma is a rare entity by itself, multiglandular coexistence of parathyroid carcinoma and parathyroid adenoma represents an extremely rare condition. Herein, we report such a rare presentation of multiglandular parathyroid neoplasm with an ectopic parathyroid carcinoma in the mediastinum and parathyroid adenoma on neck in a patient with persistent primary hyperparathyroidism (PHP). This 38-year-old female patient who initially presented with nephrolithiasis and osteopenia was subsequently diagnosed as having PHP. Following bilateral surgical neck exploration, existence of a parathyroid adenoma on the right side of neck was revealed. However, due to the persistence of hypercalcemia postoperatively, a single photon emission computed tomographic (SPECT/CT) examination was performed which showed a mass lesion in the anterior mediastinum. A surgical procedure was performed and the lesion, 10x10x3 mm in dimensions, confirmed to be a parathyroid carcinoma by histopathologic examination. At 1-year of follow-up there was no tumor recurrence or hypercalcemia. This is the first patient who had coexistent of ectopic mediastinal parathyroid carcinoma and parathyroid adenoma in the neck with persistent PHP. This case emphasises the difficulties in diagnosing and managing parathyroid disease. Multiple diagnostic studies are crucial for identification of multiple parathyroid glands in patients with persistent PHP. Keywords: Parathyroid carcinoma, parathyroid adenoma, mediastinum, primary hyperparathyroidism 394 ORTADOGU MEDICAL JOURNAL 10 (3): 394-399, 2018 Konkominan mediastinal paratiroid karsinom ve boyunda paratiroid adenoma: nadir tutulum Öz Mediastinal paratiroid karsinom nadir görülmektedir, ancak mültiglandüler paratiroid karsinom ile birlikte paratiroid adenomun görülmesi çok daha nadirdir. Persistan primer hiperparatiroidisi (PHP) olan bir hastada, mediastende ektopik paratiroid karsinoma ile birlikte boyunda paratiroid adenoma birlikteliği olan nadir multiglandüler paratiroid neoplazi vakasını sunmaktayız. Nefrolitiazis ve osteopenia şikayeti olan 38 yaşında kadın hastaya PHP tanısı kondu. Bilateral boyun eksplorasyonu sonrası, boyunda sağ tarafta paratiroid adenoma saptandı. Postoperatif hiperkalsemi devam etmesi nedeniyle, tek proton emisyonlu tomografi (SPECT/CT) taramasında ön mediastende tutulum gösterildi. Lezyona cerrahi uygulandı, 10x10x3 mm boyutunda paratiroid karsinom histopatolojik olarak doğrulandı. 1-yıllık takip sonunda, tümör rekürensi ve hiperkalsemi görülmedi. Persistan PHP’li hastada ektopik mediastende paratiroid karsinom ve boyunda paratiroid adenom birlikteliği olan ilk vakadır. Bu vaka paratiroid hastalığında tanı ve takipteki zorlukları göstermektedir. Persistan PHPT’li hastalarda multiple paratiroid bezleri gösterebilmek için multiple tanısal metodlar kullanılmalıdır. Anahtar Kelimeler: Paratiroid karsinom, paratiroid adenoma, mediasten, primer hiperparatiroidi Introduction Carcinoma of the parathyroid gland is a very rare entity that is responsible for less than 1% of all cases with primary hyperparathyroidism (PHP) and that comprises only 0.005 % of all cancer patients [1]. Although approximately 30 to 70 % of the patients with parathyroid carcinoma present with a neck mass [2], 9 patients with parathyroid carcinoma presenting with ectopic mediastinal masses have been reported in the literature [3-8]. These patients with mediastinal mass generally tended to have severe PHP [2]. Despite the common view that parathyroid carcinoma occurs in only a single parathyroid gland, very rare cases of multiglandular parathyroid carcinoma have also been observed [9]. We present a patient with concurrent ectopic left mediastinal parathyroid carcinoma and parathyroid adenoma localized on the right side of neck. Case A 38 year-old women presented with fatigue, joint pain, constipation and renal calculi. Her medical history was unremarkable. The patient had negative family history of parathyroid conditions, kidney stones or other endocrine conditions. Her physical examination was unremarkable. At admission serum total calcium was 12.5 mg/dl (Normal range (NR): 8.8-10.6), phosphorus was 2.3 mg/dl (NR:2.54.5), intact parathyroid hormone (iPTH) was 198 pg/ml (NR:11.1-79.5), creatinine was 0.6 mg/dL (NR:0.66-1.09), creatinine clearence was 95.4, urinary 24h calcium excretion was 425 mg/day (NR: 100-400), albumin was 4.7 g/ dl (NR:3.2-4.8), 25-OH vit D was 16.4 ng/mL (NR: Ad- equate > 30). patient was diagnosed as having PHP on basis of hypercalcemia, hypophosphatemia, hypercalciuria, nephrolithiasis, osteopenia and elevated PTH levels. Tc-99m-Methoxybutylisonitrile (Tc-99m- MIBI) scintigraphy performed to visualize the hyperfunctioning parathyroid tissue preoperatively and showed no parathyroid lesions. Neck ultrasound (USG) determined the presence of a solid hypoechoic nodular lesion (4x4x8 mm) at the postero-inferior aspect of the right thyroid lobe adjacent to the thyroid capsule and carotid artery. This was followed by a bilateral neck exploration and parathyroid adenoma on right side neck region was confirmed by histopathologic examination (Figure 1). During subsequent postoperative one and three days, respectively, serum iPTH (190 and 188 pg/ml) and calcium (11.6 and 11.8 mg/dl) levels remain elevated. During first month follow-up, serum total Ca was 11.4 mg/dl and iPTH was 185 pg/ml. New imaging studies were performed to definitively localize the possible missed lesion. Sestamibi-Single Photon Emission Computed Tomography (SPECT/CT) identified a soft tissue lesion with increased uptake in the anterior mediastinum and no lesion in the neck region (Figure 2). Magnetic resonance (MRI) imaging of mediastinum and neck could not detect any suspicious neck or mediastinal nodes/mass. Due to the persistence of PHP and an ectopic mediastinal lesion seen on SPECT/CT, a second surgical intervention was recommended. A left-sided thoracotomy was performed which identif (...truncated)