Anaplastic thyroid cancer and hyperthyroidism

New-onset thyrotoxicosis in a patient with anaplastic thyroid carcinoma: a diagnostic challenge

SUMMARY

Anaplastic thyroid cancer (ATC) is the type of thyroid cancer that has the worst prognosis. It usually presents as a rapidly growing cervical mass that generates compressive symptoms. Its association with thyrotoxicosis is rare. A 76-year-old woman, with no contributory history, presented with a 3-month course of fast-growing cervical tumor, associated with tenderness, cough, and weight loss. Physical examination revealed goiter, localized erythema, and a painful and stone tumor dependent on the right thyroid lobe. Due to the malignant findings of the thyroid ultrasound, the patient underwent a thyroid core needle biopsy, which indicated ATC. Laboratory tests revealed leukocytosis, decreased thyroid-stimulating hormone, elevated free thyroxine (fT4), and increased thyroperoxidase (TPO) antibodies. At the beginning, we considered that the etiology of thyrotoxicosis was secondary to subacute thyroiditis (SAT) after SARS-CoV-2 infection, due to the immunochromatography result and chest tomography findings. The result of markedly elevated TPO antibodies left this etiology more remote. Therefore, we suspected Graves' disease as an etiology; however, thyroid histopathology and ultrasound did not show compatible findings. Therefore, we suspect that the main etiology of thyrotoxicosis in the patient was the destruction of the thyroid follicles caused by a rapid invasion of malignant cells, which is responsible for the consequent release of preformed thyroid hormone. ATC is a rare endocrine neoplasm with high mortality; it may be associated with thyrotoxicosis, whose etiology can be varied; therefore, differential diagnosis is important for proper management.

LEARNING POINTS

Anaplastic thyroid cancer is the thyroid cancer with the worst prognosis and the highest mortality. The association of anaplastic thyroid cancer with thyrotoxicosis is rare, and a differential diagnosis is necessary to provide adequate treatment. Due to the current pandemic, in patients with thyrotoxicosis, it is important to rule out SARS-CoV-2 as an etiology. Anaplastic thyroid cancer, due to its aggressive behavior and rapid growth, can destroy thyroid follicular cells, generating preformed thyroid hormone release, being responsible for thyrotoxicosis.

Thyrotoxicosis with concomitant thyroid cancer

Thyrotoxicosis with concomitant thyroid cancer is rare and poorly recognized, which may result in delayed diagnosis, inappropriate treatment and even poor prognosis. To provide a comprehensive guidance for clinicians, the etiology, pathogenesis, diagnosis and treatment of this challenging setting were systematically reviewed. According to literatures available, the etiologies of thyrotoxicosis with concomitant thyroid cancer were categorized into Graves' disease with concurrent differentiated thyroid cancer (DTC) or medullary thyroid cancer, Marine-Lenhart Syndrome with coexisting DTC, Plummer's disease with concomitant DTC, amiodarone-induced thyrotoxicosis with concomitant DTC, central hyperthyroidism with coexisting DTC, hyperfunctioning metastases of DTC and others. The underlying causal mechanisms linking thyrotoxicosis and thyroid cancer were elucidated. Medical history, biochemical assessments, radioiodine uptake, anatomic and metabolic imaging and ultrasonography-guided fine-needle aspiration combined with pathological examinations were found to be critical for precise diagnosis. Surgery remains a mainstay in both tumor elimination and control of thyrotoxicosis, while anti-thyroid drugs, beta-blockers, 131I, glucocorticoids, plasmapheresis, somatostatin analogs, dopamine agonists, radiation therapy, chemotherapy and tyrosine kinase inhibitors should also be appropriately utilized as needed.

Remarkable Presentation: Anaplastic Thyroid Carcinoma Arising from Chronic Hyperthyroidism

Background

Undifferentiated anaplastic carcinoma rarely develops from chronic hyperthyroidism. Although acute hyperthyroidism can develop prior to anaplastic transformation, chronic hyperthyroidism was thought to be a protective measure against thyroid malignancy.

Methods

A 79-year-old female presented acutely to the hospital with dyspnea. She had been taking methimazole for chronic hyperthyroidism due to toxic thyroid nodules, previously biopsied as benign. Upon admission, imaging showed tracheal compression, requiring a total thyroidectomy with tracheostomy for airway management.

Results

Pathology demonstrated undifferentiated anaplastic thyroid carcinoma. The patient passed away shortly after hospital discharge. Despite treatment with methimazole for many years, abrupt enlargement of her toxic multinodular goiter was consistent with malignant transformation. Chronic hyperthyroidism and toxic nodules are rarely associated with thyroid malignancy, with only one previous report documenting association with anaplastic thyroid carcinoma.

Conclusion

Progressive thyroid enlargement and acute worsening of previously controlled hyperthyroidism should promote concern for disease regardless of baseline thyroid function.

Anaplastic thyroid carcinoma initially presented with abdominal cutaneous mass and hyperthyroidism

A 63-year-old female was admitted to our hospital with a tender abdominal wall mass about 15 cm in diameter, which she had for 1 month. About 1 week earlier, the patient had also perceived a mass in the neck area. Computed tomography revealed huge thyroid and periumbilical masses. The thyroid hormone levels were consistent with a hyperthyroid state. Pathological examination of the thyroid mass was compatible with anaplastic thyroid carcinoma (ATC) and the abdominal cutaneous mass was shown to be metastatic ATC. Despite palliative radiotherapy and chemotherapy, the patient died of respiratory failure on her 63rd day of hospitalization. This case demonstrates that abdominal cutaneous metastasis and hyperthyroidism can occur as initial manifestations of ATC. To our knowledge, this is the first reported case.

Recurrent thyroid storm induced by heretofore unrecognised causes in a patient with thyroid cancer

An unusual encounter of a thyroid storm, on two separate occasions, is reported in a patient with metastatic differentiated thyroid cancer following initially direct trauma to, and later tumour embolisation of, a metastatic skeletal lesion. Shortly after a fall, our patient presented with pain and swelling in the right shoulder, high fever, change in mental status, anorexia, nausea and vomiting, tachycardia and dehydration. The laboratory tests were consistent with hyperthyroidism. As the patient improved, arterial embolisation of the large right humerus metastasis was performed to decrease the tumour burden. The patient, however, developed a similar clinical and biochemical picture to that at her presentation, with a very high free thyroxine (T(4)) level, a few days after successful embolisation. Treatment of the thyroid storm was initiated and the patient eventually improved. Awareness of such occurrences is helpful in early diagnosis and effective management of this potentially fatal complication.

Anaplastic thyroid cancer

Anaplastic thyroid cancer is an uncommon, typically lethal malignancy of older adults with no effective systemic therapy. The mean survival time is usually less than 6 months from the time of diagnosis and, unfortunately, this outcome is not fundamentally altered by available treatments. Histologic tissue confirmation is recommended if the diagnosis is not absolutely certain to exclude tumors with better prognosis or that require different treatment. Patency of the airway should be kept in mind throughout the patient's course and individuals with impending airway obstruction, in the absence of imminent death from other sites of disease, should be considered for a tracheostomy to secure the airway. Enrollment in meaningful clinical trials should be given the highest priority at all decision points.