Case report: a camouflaged parathyroid carcinoma with initial misdiagnosis

Intrathyroidal parathyroid carcinoma presenting as thyroid nodule: Case report of unusual location

Introduction

Parathyroid carcinoma (PC) is considered a rare and uncommon malignancy. Its prevalence is about 0.005% of all cancers. Intrathyroidal location is rare, rendering preoperative diagnosis tedious. Until now, around 700 cases of PC have been documented, reportedly, among them, less than 21 cases of intrathyroidal parathyroid carcinoma have been described in the literature. We report a case of intrathyroidal PC that was taken for a suspicious thyroid nodule, with a literature review.

PRESENTATION OF THE CASE: Our case is an asymptomatic intrathyroidal PC imitating a suspicious thyroid nodule, in a 54-year-old woman. A literature review was performed about clinical, radiological features, histopathological findings, and therapeutic options.

Discussion

The diagnosis of asymptomatic intrathyroidal parathyroid carcinoma, similar to our case report, is even more difficult, our patient had no symptoms of hypercalcemia. Surgery is the cornerstone of the treatment. A better chance to cure this disease is conditioned by complete surgical resection with negative margins microscopically, that was the case of our patient with a very good clinical course after 12 months of follow-up.

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Parathyroid Carcinoma Is an Uncommon Endocrine Malignancy, Making Approximately 0.005% of All Cancers and 0,5%–2% of Patient With Primary Hyperparathyroidism.

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Intrathyroidal Location Is Rare and Make Preoperative Suspicion and Diagnosis Challenging.

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Approximately 700 Cases of Parathyroid Carcinoma Have Been Reported to Date and, to The Best of Our Knowledge, Less Than 24 Cases of Intrathyroidal Parathyroid Carcinoma Has Been Previously Documented.

Intrathyroidal parathyroid carcinoma: a case report and literature review

Parathyroid carcinoma is an uncommon endocrine malignancy comprising 0.5%–2% of patients with primary hyperparathyroidism. The probability of an intrathyroidal location is low (0.2%) and make preoperative suspicion and diagnosis challenging. Less than 20 cases of intrathyroidal parathyroid carcinoma have been reported. We introduce a case of intrathyroidal parathyroid carcinoma mimicking a suspicious thyroid nodule, and review the literature, with a focus on the role of adjuvant radiotherapy.

Bones and Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a disease caused by excessive and inappropriate secretion of parathyroid hormone resulting in hypercalcemia. It is usually diagnosed incidentally in the face of hypercalcemia, a complication such as osteoporosis or, more rarely, a renal complication with lithiasis. The clinical presentation reflects hypercalcemia and involves several organs, mainly the cardiovascular system, bones, and kidneys. However, most patients with PHPT are asymptomatic. The diagnosis is made based on laboratory tests. It is easy when serum calcium and parathyroid hormone levels are high, but difficult when one of these two values is normal. Normocalcemic PHPT can be diagnosed only after ruling out all causes of secondary hyperparathyroidism. Parathyroid imaging cannot diagnose it but guides the surgeon and rules out an associated thyroid abnormality. The reference treatment is surgery. The surgical indication is based on the presence or risk of complications, and it is the only treatment that prevents fractures. Pharmaceutical treatments have only limited effects on complications and are reserved for cases where surgery is contraindicated. After parathyroid surgery, the use of bisphosphonates must be avoided as they seem to interfere with the parathyroidectomy's fracture-preventing effects. If surgery is not indicated, a plan for monitoring laboratory values, bone density, and renal function will be established.

Hypercalcemia of Malignancy Revealing a Parathyroid Carcinoma with Hepatic Metastasis: A Case Report and Literature Review

Parathyroid carcinoma is a very rare malignant tumor of the parathyroid gland. This cancer poses a great diagnostic and therapeutic difficulty due to its rarity and the absence of a characteristic clinical and paraclinical picture. The diagnosis is histological but is not always easy. Surgery remains the only curative treatment, and cervical radiotherapy can be discussed. Good prognostic factors are complete monobloc tumor resection, and bad prognostic factors are the presence of lymph node metastases at diagnosis, distant metastases, and nonsecreting carcinomas.