Case Report of Rare Parathyroid Tumor with Atypical Presentation and Early Diagnosis

Parathyroid carcinoma is a rare condition, accounting for 1% of cases of hyperparathyroidism. Other causes of hyperparathyroidism main group are single adenoma and parathyroid hyperplasia. The clinics presented by the patients are typical of hyperparathyroidism (fatigue, weakness, weight loss, and anorexia), bone impairment, pain, and fractures, in addition to affecting the renal system The diagnosis of parathyroid carcinoma is most often done postoperatively by means of a histological study. The case report is a 49-year-old male patient who came to the emergency room of Mackenzie Evangelical University Hospital complaining of progressive “muscle weakness” and “joint” that started about 2 months ago. To raise the suspicion of parathyroid carcinoma, it is essential to perform the correlation of the clinical picture, biochemical values, and imaging exams, but to obtain the definitive diagnosis, intraoperative recognition of the tumor and the result of the histopathological examination of the resected tumor are necessary.

Parathyroid Tumors: Molecular Signatures

Parathyroid tumors are rare endocrine neoplasms affecting 0.1–0.3% of the general population, including benign parathyroid adenomas (PAs; about 98% of cases), intermediate atypical parathyroid adenomas (aPAs; 1.2–1.3% of cases) and malignant metastatic parathyroid carcinomas (PCs; less than 1% of cases). These tumors are characterized by a variable spectrum of clinical phenotypes and an elevated cellular, histological and molecular heterogeneity that make it difficult to pre-operatively distinguish PAs, aPAs and PCs. Thorough knowledge of genetic, epigenetic, and molecular signatures, which characterize different parathyroid tumor subtypes and drive different tumorigeneses, is a key step to identify potential diagnostic biomarkers able to distinguish among different parathyroid neoplastic types, as well as provide novel therapeutic targets and strategies for these rare neoplasms, which are still a clinical and therapeutic challenge. Here, we review the current knowledge on gene mutations and epigenetic changes that have been associated with the development of different clinical types of parathyroid tumors, both in familial and sporadic forms of these endocrine neoplasms.

Ex vivo intact tissue analysis reveals alternative calcium-sensing behaviors in parathyroid adenomas

Context The biochemical basis for clinical variability in primary hyperparathyroidism (PHPT) is poorly understood. Objectives To define parathyroid tumor biochemical properties associated with calcium sensing failure in PHPT patients, and to relate differences in these profiles to variations in clinical presentation. Design Pre-operative clinical data were evaluated for correlation to parathyroid tumor biochemical behavior. Setting An endocrine surgery referral center at a large, public university hospital. Patients and Other Participants A sequential series of 39 patients undergoing surgery for PHPT. Main Outcome Measures An intact tissue, ex vivo interrogative assay was employed to evaluate the calcium-sensing capacity of parathyroid adenomas relative to normal donor glands. Tumors were functionally classified based on calcium dose-response curve profiles, and clinical parameters were compared among the respective classes. Changes in the relative expression of CASR, RGS5, and RCAN1, three key components in the calcium/PTH signaling axis were evaluated as potential mechanisms for calcium-sensing failure. Results Parathyroid adenomas grouped into three distinct functional classes. Tumors with diminished calcium sensitivity were the most common (18 of 39) and were strongly associated with reduced bone mineral density (p=0.0009). Tumors with no calcium sensing deficit (11 of 39) were associated with higher pre-operative PTH (p = 0.036). A third group (6/39) displayed a non-sigmoid calcium/PTH response curve; four of these six tumors expressed elevated RCAN1. Conclusions Calcium-sensing capacity varies among parathyroid tumors but down-regulation of the calcium sensing receptor (CASR) is not an obligate underlying mechanism. Differences in tumor calcium responsiveness may contribute to variations in PHPT clinical presentation.

SPECT/CT in the diagnosis of ectopic parathyroid adenoma (case report)

Case study: a parathyroid tumor ectopic to the mediastinum. The diagnostic capabilities and advantages of the 99mТс-sestamibi SPECT/CT hybrid method in the preoperative localization of abnormally located parathyroma are demonstrated.

Brown tumor due to primary hyperparathyroidism resulting in acute paraparesis: Case report and literature review

Background: Brown tumor (Osteoclastoma) is a rare benign, focal, lytic bone lesion most commonly attributed to a parathyroid adenoma; it occurs in approximately 5% of patients with primary hyperparathyroidism, and 13% of patients with secondary hyperparathyroidism. Most tumors are located in the mandible, pelvis, ribs, and large bones; only rarely is it found in the axial spine. Case Description: A 37-year-old male with primary hyperparathyroidism presented with an MR-documented T4 and T5 brown tumor (Osteitis Fibrosa Cystica) resulting in an acute paraparesis. The patient successfully underwent excisional biopsy of an expansile, enhancing, bony destructive lesion at the T4-5 level. Subsequently, he required subtotal excision of a left upper parathyroid tumor. Conclusion: Patient with primary hyperparathyroidism may acutely present with paraparesis attributed to brown tumors of the spine warranting emergent operative decompression.

MON-920 Pediatric Parathyroid Carcinoma Presenting With Acute Progressive Genu Valgum

BACKGROUND: Parathyroid carcinoma (PC) is exceptionally rare in children and its clinical features are poorly understood. Available reports have identified that very high serum calcium and parathyroid hormone levels would be expected in this disease. Definitive therapy for PC requires en bloc resection of the parathyroid tumor to reduce the risk of disease recurrence. Unfortunately, there are very few treatment options for metastatic PC and patients with recurrent PC have a high risk of mortality related to their disease. Because of the rarity of the condition, there are very limited data including pediatric patients. Case: A previously healthy 13-year-old girl initially presented to primary care with bilateral foot and ankle pain in the context of acute and progressive genu valgum, referred to the orthopedic clinic. Lab evaluation prompted by imaging demonstrated severe hypercalcemia (15.6 mg/dL) and hyperphosphatasia (Alkaline phosphatase 2056 units/L). She was urgently referred to our clinic where we found her to have a firm right sided neck mass within the thyroid. Lab testing at that time confirmed profound hyperparathyroidism (PTH 2970 pg/mL). Neck ultrasound confirmed the presence of a 5.8 cm hypoechoic lesion adjacent to the right lower lobe of the thyroid. The patient received IV fluid resuscitation before undergoing urgent parathyroid surgery. The parathyroid lesion was grossly adherent to the thyroid gland and she received en bloc resection of the tumor and right lobe of the thyroid. Post-operatively, PTH rapidly declined to <3.4 and she developed a prolonged hypocalcemic phase. PTH function improved, but she continued to require high doses of calcium carbonate to address hungry bone syndrome over subsequent weeks. Comprehensive evaluation included testing for genetic mutations, deletions, and duplications in CASR, CDC73, CDKN1B, MEN1 and RET, all of which were negative. Extensive genetic testing of the parathyroid tumor did not identify any specific mutations which have been previously associated with PC. Six months post-operatively, her labs have vastly improved, although she has clinical evidence of PTH resistance and her alkaline phosphatase has not yet normalized. Neck ultrasound, F-18 FDG PET/MRI imaging and Sestamibi scans show no evidence of persistent disease. Conclusions: While parathyroid carcinoma is extremely rare in pediatric patients, the diagnosis must be considered in cases of hypercalcemia with marked elevations in PTH and palpable neck mass. Although rarely described, bone changes related to PC may be dramatic and may result in lasting morbidity - including genu valgum requiring surgical intervention as well as prolonged hungry bone syndrome and metabolic bone disease. Genu valgum is a unique pediatric feature of this disease because this may only evolve in individuals whose physes are open.

PARATHYROID CARCINOMA WITH INTRATHYROID LOCATION: CASE FROM PRACTICE

Carcinoma of the parathyroid gland is a rare malignant tumor of the person, which manifests itself clinical syndrome of hyperparathyroidism. The tumor is characterized by structural signs of invasive growth and is characterized by an unfavorable clinical prognosis, often accompanied by metastasis and the formation of relapses. The article provides background information about the incidence of parathyroid carcinoma, the gender and age characteristics of patients with this disease, options for localization of the tumor in the gland itself (typical topic of the neoplasm), in other areas of the neck, thyroid, thymus, and so on. We discuss the features of clinical manifestations of parathyroid carcinoma, among which the most typical are manifestations of hyperparathyroidism and hypercalcemia, and also provide figures for five - and ten-year survival. The article presents the author’s observation of parathyroid carcinoma with an intrathyroid location in a 64-year-old man. After the examination, the patient underwent a cervicotomy with revision of the areas of the typical location of the parathyroid gland in the neck, hemithiroidectomy on the left with a parathyroid tumor incorporated in the thyroid tissue, which was later proved using immunohistochemical research methods. The article details the macroscopic, microscopic, and immunohistochemical characteristics of the operating material. A special feature of the case is a rare atypical intrathyroid localization of parathyroid carcinoma.