Parathyroid Carcinoma in the Setting of Tertiary Hyperparathyroidism: Case Report and Review of the Literature

Introduction. Parathyroid carcinoma is one of the rarest cancers in normal population, and it is extremely uncommon in the setting of tertiary hyperparathyroidism. Indeed, only 24 cases have been reported in the literature. Presentation of the Case. We report the case of parathyroid carcinoma in a 51-year-old man, with a history of end-stage renal disease due to a horseshoe kidney treated with haemodialysis since 2013. He came to our attention due to an increase in calcium and parathyroid hormone serum levels. Neck ultrasound (US) showed a solid hypodense mass, probably the right inferior parathyroid gland, with an estimated size of 25 × 15 × 13 mm; the 99mTc-sestamibi SPECT/CT scan revealed a large radiotracer activity area in the right cervical region, compatible with a hyperfunctioning right inferior parathyroid gland. So, a tertiary hyperparathyroidism diagnosis was made. In April 2018, resection of three parathyroid glands was performed. Histopathological examination demonstrated the right inferior parathyroid gland specimen to be a parathyroid carcinoma, due to the presence of multiple, full-thickness, capsular infiltration foci, and a venous vascular invasion focus. Discussion. Diagnosis of parathyroid carcinoma in tertiary hyperparathyroidism is remarkably complex because of the lack of clinical diagnostic criteria and, in many cases, is made postoperatively at histopathological examination. Conclusion. To date, radical surgery represents the mainstay of treatment, with a five- and ten-year survival rates overall acceptable.

SAT-349 Cinacalcet Resistant Tertiary Hyperparathyroidism with One Large Parathyroid Gland

Tertiary hyperparathyroidism is thought to develop after long term secondary hyperparathyroidism, such as CKD on dialysis. In This case, all parathyroid glands are significantly enlarged. We report a case of an 84-year-old female with a past medical history of ESRD on HD and recurrent nephrolithiasis who was found to have an enlarged multinodular goiter with the dominant mass in the lower pole of the right gland measuring about 4.7 cm on thyroid ultrasound. Blood work was done which showed elevated intact PTH levels at 2720 pg/mL (12–88). Her calcium level was normal at that time at 10.5 mg/dL (8.6–10.8) with an albumin of 4.2 g/dL (3.5–5.7), and a phosphorus of 5.7 mg/dL (2.5–4.5). Patient had a DEXA scan which showed severe osteoporosis in the lumbar spine, left hip, and right forearm. Patient had increased PTH levels despite being on Cinacalcet. She had a nuclear medicine parathyroid scan with SPECT CT which showed increased uptake along the right inferior thyroid concerning for a large right lower parathyroid adenoma or functional thyroid nodule. FNA of the nodule was done and showed colloid nodule but PTH wash showed elevated PTH at 7634 pg/mL. She was referred for right lower parathyroidectomy and Cinacalcet was discontinued prior to surgery. She had right and left inferior parathyroidectomy and 4 gland exploration. Pathology showed the right inferior parathyroid gland to be markedly hyper-cellular, weighing 36 grams consistent with hyperplasia and the left inferior parathyroid gland to be slightly hyper-cellular parathyroid gland consistent with hyperplasia. No evidence of malignancy was noted on pathology. Prior to surgery her calcium level of 10.6 mg/dL which went down to 9.6 mg/dL post-operatively. Patient then developed severe hypocalcemia and hungry bone syndrome following the surgery requiring a calcium drip for 3 days post-operatively. Was changed to oral calcium but required large amounts of calcium gluconate and calcitriol supplementation and an extended hospital stay of 13 days. However, throughout the hospital stay, PTH levels continued trending back up to 239 which may represent either increased activity from remaining parathyroid glands or residual parathyroid adenoma with incomplete resection. Post-operative US neck showed Post-surgical collection in the lower pole of the right gland measuring 4.8 cm compatible with recent resection. In conclusion, tertiary hyperparathyroidism can develop due to one enlarged parathyroid gland or an adenoma, which can be resistant to cinacalcet.

Adult Ectopic Cervical Thymic Tissue in relation to a Parathyroid Adenoma and a Papillary Thyroid Carcinoma: A Report of Two Cases

Ectopic cervical thymus is a rare congenital anomaly, which results because of the failure of complete descent of the thymus. They are incidental findings in the young and may disappear during the early years of life; however, they have rarely been described in adults. Some of them may undergo hyperplasia or neoplastic transformation and become visible or cause symptoms. We report two rare cases of incidentally detected cervical thymic tissue in adults. In one case, the thymic tissue was seen adjacent to a parathyroid adenoma of the left inferior parathyroid gland. In the other, it was seen adjacent to the left inferior parathyroid gland in a case of papillary thyroid carcinoma. In both these cases, the ectopic thymic tissue was diagnosed as a result of pathological examination, not clinically by macroscopic appearance during operation or radiological evaluation. The finding needs to be noted as these ectopic foci can occasionally give rise to hyperplasia and neoplasms of the thymus.

Postoperative Horner’s syndrome following excision of incidental cervical ganglioneuroma during hemithyroidectomy and parathyroid gland exploration

This 49-year-old woman was referred to ear, nose and throat (ENT) with primary hyperparathyroidism. Imaging studies failed to localise the adenoma so she required four-gland parathyroid exploration. She also required diagnostic left hemithyroidectomy as she had a U3 nodule with multiple insufficient fine needle aspirations (FNAs). Intraoperatively, the left thyroidectomy proceeded uneventfully. No convincing left inferior parathyroid gland was identified however palpation revealed a 1 cm mass just medial to carotid artery. This was excised as probable ectopic parathyroid gland. She was discharged two days later. Thirteen days postoperatively she attended Eye Casualty with a left-sided Horner’s syndrome. A CT angio of aortic arch was normal. She was reviewed at ENT outpatients. Histopathology report of the expected ectopic parathyroid gland returned as benign ganglioneuroma, likely arising from her left sympathetic chain. Horner’s syndrome is a common side effect from excision of ganglioneuromas, but an incredibly rare side effect from thyroid or parathyroid surgery.

BPI19-020: A New Protecting Method for the Inferior Parathyroid Gland in situ: The Meticulous Thyrothymic Ligament Dissection Technique

Objective: To explore the anatomic features and the dissection technique of thyrothymic ligament (TTL) and to explore the clinical significance of protecting the inferior parathyroid gland (IPTG) with this structure. Method: Dissect the TTL of patients who receive initial thyroid surgery in our center, describe the structural features of TTL, and investigate the positional relationship of TTL and IPTG. Results: TTL is a kind of adipose connective tissue that is wide at the bottom and narrow at the top, accompanying with the inferior thyroid vein, from the thymus to the thyroid. Over 70% TTL are attached to the lower pole and the lower one-third dorsal of thyroid, containing fat and vessels. About 121 patients have undergone this dissection, totally dissected 194 sides, 143 sides had TTL (73.7%). About 63.4% IPTGs are located in the thymus-thyrothymic ligament-IPTG complex (TLIC), and nearly 70.6% IPTG can be proactively identified and located by the TTL during the operation. The incidence rate of postsurgical hypoparathyroidism is 14.9%. According to whether the dissection is successful, the IPTG can be described into 2 types, the ligament type (L) and the non-ligament type (N), and each type can be described into different subtypes.

A case of hypercalcaemic crisis secondary to coexistence of primary hyperparathyroidism and Graves’ disease

A 46 year-old female patient presented to the hospital with ongoing and progressively increasing fatigue, severe nausea and vomiting, loss of appetite, constipation, palpitations and somnolence. Laboratory evaluation revealed a severe hypercalcaemia and overt hyperthyroidism. She was diagnosed with primary hyperparathyroidism accompanied by Graves’ disease. The patient underwent total thyroidectomy and right inferior parathyroid gland adenoma excision on the 24th day of her admission to the hospital after calcium levels and free thyroid hormone levels were brought to normal ranges. We suggest that a possibility of simultaneous thyrotoxicosis and primary hyperparathyroidism in cases presenting with a hypercalcaemic crisis should be considered

SOME ASPECTS OF EARLY DEVELOPMENT OF THE THYMUS: EMBRYOLOGICAL BASIS FOR ECTOPIC THYMUS AND THYMOPHARYNGEAL DUCT CYST. Algunas observaciones acerca del temprano desarrollo del timo: bases embriológicas del timo ectópico y del quiste del conducto timofar

Introducción. El objetivo principal de nuestro trabajo es el estudio histológico del desarrollo del timo humano entre la 5ª y la 8ª semana de gestación. Describimos varios términos embriológicos poco usados como: timo secundus, descensus thymi (la base embriológica para situar el timo en la garganta), ductus timicus (la base embriológica para el defecto innato llamado conducto timofaríngeo con posibilidad de formar un quiste). Material y método. Nuestras observaciones se basan en la investigación de 18 embriones humanos entre la 6ª y la 8ª semana de gestación. Resultados. La base del timo es común con la base de las glándulas paratiroideas. Es comparable con las bolsas faríngeas (saccus pharyngeus) en los embriones largos de 8 a 9 mm. La proliferación endodermal del epitelio en el tercer foco faríngeo (focus faringeus 3) es muy visible. La parte craneal y la parte dorsal son la base de origen de las glándulas paratiroideas inferiores. La parte caudal y la parte ventral son la base para el timo. Hemos observado también la notable proliferación del epitelio en la segunda bolsa faríngea, llamado por algunos autores Timo secundus. En nuestra opinión, en el ser humano no se forma un timo funcional en este lugar y la proliferación del epitelio en la mayoría de los casos, se detiene pronto. Conclusión. En este trabajo ofrecemos una vista general sobre la importancia clínica del desarrollo del timo y la descripción de los defectos innatos más frecuentes del mismo. Introduction. The aim of our morphological study is to describe the development of human thymus from 5th up to 8th week after fertilization in the context of its phylogenesis. We explicate some of the “forgotten” embryological terms with respect to their functions in thymic development, such as “thymus secundus”, “descensus thymi” (an embryological basis for cervical thymus) and “ductus thymicus” (an embryologic basis for a congenital anomaly called thymopharyngeal duct with possible thymic cyst). Material and methods. Our findings are based on the study of 18 human embryos from 6th to 8th week of development. Results. The first primordia of the thymus and parathyroid glands within the endoderm of pharyngeal pouches can be seen in 8 to 9 mm crown-to-rump-length stages. The most evident epithelial proliferation is visible in the paired third pharyngeal pouch (saccus pharyngeus tertius): the cranial dorsal part of pharyngeal pouch initiates the inferior parathyroid gland and the caudal ventral part of the pouch gives rise to the epithelial thymus. We found an obvious endodermal epithelial proliferation also in the second pharyngeal pouch. Some authors depict this proliferation as “thymus secundus”, but the proliferation of endoderm close down and the functional second thymus does not develop in human embryos. Conclusion. In our work we also review the clinical significance of early thymus development, as well as the most common developmental anomalies of thymus.