Isolated cardiac metastasis from papillary thyroid cancer: prolonged survival with late diagnosis related to inadequate positron emission tomography preparation

Case Report: Acute arterial occlusion of the right lower extremity due to left atrial invasion from pulmonary metastases of thyroid cancer

Cardiac metastases of thyroid cancer are rare. The most common metastatic route is through lymphatic or hematogenous spread to the right side of the heart. Direct invasion of metastases from other adjacent organs to the left side of the heart is even rarer. In many cases, the disease progresses asymptomatically, and symptoms appear only when it is already fatal. A 68-year-old woman underwent total thyroidectomy and right-side lymph node dissection for papillary thyroid cancer and multiple lung metastases 7 years previously. The patient was referred to our hospital due to sudden pain in the right lower extremity and motor disturbance. Computed tomography revealed acute arterial occlusion of the right lower extremity due to tumor dispersal from a left atrial invasion caused by multiple pulmonary metastases of thyroid cancer, and only emergency thrombectomy was performed. Although blood flow was restored, the patient died of respiratory failure 2 months after the procedure. Radical resection is considered difficult in cases of direct invasion of metastases from other adjacent organs because multiple metastases have often already occurred. Therefore, in the terminal stage, it might be too invasive to resect a tumor only to prevent embolism recurrence. The treatment strategy should depend on the patient's prognosis and choice.

Cardiac Metastasis from Medullary Thyroid Cancers with Long-Term Survival under Vandetanib

BACKGROUND

Cardiac metastases from thyroid cancers are uncommon with a poor prognosis. There is a lack of long-term follow-up studies.

CASES

We report 2 cases of cardiac metastasis from medullary thyroid cancer (MTC). Both patients presented limited metastatic disease apart from a cardiac metastasis. The initial diagnosis was challenging and was facilitated by functional imaging with an immuno-PET-CT using an anti-CEA bispecific antibody and a ⁶⁸Ga-labeled peptide. Both patients were treated with the multitarget kinase inhibitor vandetanib with prolonged stability. The first patient was alive at the last follow-up, 14 years after the diagnosis of cardiac metastasis. The second patient required surgical excision of the cardiac mass because of disease progression under vandetanib.

CONCLUSION

These cases illustrate long-term survival and effectiveness of clinical management of 2 patients who developed cardiac metastases from MTC, in the current era of personalized medicine with targeted therapy.

Radiotheragnostics Paradigm for Radioactive Iodine (Iodide) Management of Differentiated Thyroid Cancer

This review of radioactive iodide treatment (RAIT) extends from historical origins to its modern utilization in differentiated thyroid cancer (DTC). The principles embedded in the radiotheragnostics (RTGs) paradigm are detailed. The diverse approaches in current practice are addressed, and this broad variability represents a major weakness that erodes our specialty's trust-based relationship with patients and referring physicians. The currently developing inter-specialty collaboration should be hailed as a positive change. It promises to clarify the target-based terminology for RAIT. It defines RAIT of post total thyroidectomy (PTT), presumably benign thyroid as 'remnant ablation' (RA). 'Adjuvant treatment' (AT) referrers to RAIT of suspected microscopic DTC that is inherently occult on diagnostic imaging. RAIT directed at DTC lesion(s) overtly seen on diagnostic imaging is termed 'treatment of known disease' (TKD). It was recently recognized that a 'recurrent' DTC is actually occult residual DTC in the majority of cases. Thyroglobulin with remnant uptake concord (TRUC) method (aka Tulchinsky method) was developed to validate that a benign remnant in the post-thyroidectomy neck bed, as quantified by the RAI uptake, is concordant with a measured thyroglobulin (Tg) level at the time of the initial post-thyroidectomy evaluation. It allows recognition of occult residual DTC contribution to post-thyroidectomy Tg. Case examples demonstrate the application of the TRUC method for a logical selection of a specific RAIT category, using imaging-guided identification and management of RAI-avid versus RAI-nonavid residual DTC, i.e. the radiotheragnostics paradigm.

Whole body computed tomographic characteristics of skeletal and cardiac muscular metastatic neoplasia in dogs and cats

Muscular metastatic neoplasia has been reported to be rare in domestic animals, however previous studies were based primarily on necropsy findings. The purpose of this retrospective study was to describe whole body computed tomography (CT) characteristics of confirmed muscular metastases in a cohort of dogs and cats presented for oncology evaluation. Medical records of 1201 oncology patients were reviewed. Included animals underwent pre and postcontrast whole body CT, and CT-guided tru-cut biopsy or fine needle aspiration of one or more metastatic lesions. Twenty-one dogs and six cats met inclusion criteria, representing 2.08% of all canine oncology patients and 3.1% of all feline oncology patients. Mean age was 9.6 years. Postcontrast CT characteristics included well-demarcated, oval-to-round lesions with varying enhancement patterns: ring enhancing (n = 16), heterogeneously enhancing (n = 8), or homogeneously enhancing (n = 5). Five animals showed concurrent and varying nodular patterns. In seven cases (five dogs and two cats), one single muscular nodule was observed. In 20 cases, two or more lesions were observed. In two cases, cardiac hypodense nodules were observed in the postcontrast CT, while appearing isodense in the precontrast study. Necropsy confirmed neoplasia in both of them. Locations of muscular metastases included epaxial/paraspinal muscles of the cervical, thoracic, and lumbar spine (n = 18), superficial muscles of the thoracic wall (n = 13), scapular/shoulder region (n = 3), hind limb (n = 3), and abdominal wall muscles (n = 1). Findings supported the use of pre and postcontrast whole body CT for oncologic staging in dogs and cats, especially for primary tumors characterized by a high metastatic rate.