Hürthle cell thyroid carcinoma metastatic to the sigmoid colon

Image-guided radiation therapy using surgical clips for localization of colonic metastasis from thyroid cancer

A 67-year old man with a history of papillary thyroid cancer (PTC) presented with metastatic disease to the left colon in the form of a 6.1x1.0 cm bleeding, ulcerated mass. Radiopaque surgical clips were used as fiducial markers to localize the gross tumor volume (GTV) as well as the corresponding clinical target volume (CTV) and planning target volume (PTV). Daily cone beam computed tomography (CBCT) image guidance was utilized to verify the tumor position. Inter- and intrafraction movement of the tumor mass was assessed. Gastrointestinal bleeding was controlled using palliative image-guided radiation therapy (IGRT).

Solitary spinal metastasis of Hürthle cell thyroid carcinoma

Hürthle cell carcinoma is a rare variant of differentiated thyroid cancer that occasionally forms distant metastases. However, even in the presence of metastases, patients with Hürthle cell carcinoma have a relatively good prognosis. There are few reports of Hürthle cell carcinoma metastases to the vertebral column, and none describing aggressive resection of spinal metastases. Here, we report a 68-year-old woman with a solitary metastasis of Hürthle cell carcinoma to the T1 vertebral body causing severe kyphotic deformity, myelopathy, and pain. The patient was treated with aggressive excisional decompression of the spinal cord and T1 vertebral body resection from an entirely posterior approach. Reconstruction and stabilization of the anterior spine was accomplished with a transforaminal lumbar interbody fusion allograft spacer and posterior instrumentation. We discuss aspects of the diagnosis, management, patient selection, and surgical treatment of metastatic Hürthle cell carcinoma in reference to the literature.

Metastases of well-differentiated thyroid cancer to the gastrointestinal system

BACKGROUND

The incidence of distant metastases at the time of initial presentation of well-differentiated thyroid cancer is approximately 4%. During the course of treatment and follow-up, the prevalence of distant metastases ranges from 2% in low-risk patients up to 33% in high-risk patients. When present, distant metastases occur primarily in the lungs and, to a lesser extent, in bones. Of all sites for distant metastasis, gastrointestinal metastases of thyroid cancer are very uncommon and account for 0.5-1% of all distant metastases.

SUMMARY

Indications of metastases to the gastrointestinal system can be overlooked with traditional total body radioisotope scans that image the abdomen, including both diagnostic and posttherapy scans, because of the confounding presence of physiologic enteric radioactivity. When suspected in high-risk patients, other imaging procedures such as computed tomography, magnetic resonance imaging, and PET-computed tomography should be considered. This communication will review thyroid cancer metastases to the gastrointestinal system in regard to occurrence rate, diagnosis, and treatment.

CONCLUSIONS

Because of the extreme rarity of patients with metastases of thyroid cancer to the gastrointestinal tract, long-term follow-up data as well as information on prognosis are very limited. Aggressive management may provide symptomatic relief or palliation, but cure is unlikely once widespread metastases supervene. Attempts at complete or near-complete surgical resection of the metastases invading the digestive tract, followed by 131-I treatment, offer the best opportunity for improvement but will only rarely result in cure in selected patients.

Intra-abdominal insular thyroid carcinoma metastasis

BACKGROUND

In thyroid cancer, metastases to intra-abdominal solid organs are uncommon and intra-peritoneal metastases are extremely rare. Here we present the management and outcome of a young patient with a large radioiodine resistant intra-peritoneal metastasis of insular thyroid cancer.

SUMMARY

A 28-year-old woman with known radioiodine resistant metastatic insular (poorly differentiated) thyroid carcinoma and multiple previous resected metastases presented with acute onset of bowel obstruction due to a large pelvic mass. The pelvic mass was resected and histologically confirmed to be an insular thyroid carcinoma metastasis. She made an uneventful recovery from her surgery and continues to have a good quality of life despite low volume metastatic disease.

CONCLUSION

As this patient demonstrates, a rational but aggressive surgical approach is warranted for patients with radioiodine-resistant metastatic thyroid disease.

Hurthle cell neoplasms of the thyroid: sonographic appearance and histologic characteristics

OBJECTIVE

The purpose of this study was to determine the sonographic features of Hürthle cell neoplasms (HCNs) of the thyroid.

METHODS

We retrospectively analyzed the sonographic appearance of 15 histologically proven HCNs in 15 patients aged 16 to 70 years (mean age, 44 years). Sonographic features that were reviewed included the size and echogenicity of the tumors, the presence of cystic areas or calcifications, and detectable blood flow on color Doppler imaging. Correlation of sonographic findings with pathologic results was performed.

RESULTS

The tumors ranged from 0.4 to 7 cm in diameter, but most were less than 3 cm in diameter. Four (27%) of the 15 tumors were homogeneously hypoechoic. Two tumors (13%) were predominantly hypoechoic with isoechoic areas to thyroid parenchyma. Two (13%) neoplasms were isoechoic to thyroid parenchyma. Four (27%) tumors were predominantly isoechoic, containing hypoechoic areas, and 3 (20%) tumors were hyperechoic. Three neoplasms contained cystic components. None of the tumors contained calcifications. One tumor was avascular on Doppler examination. One neoplasm showed only peripheral blood flow. Thirteen tumors showed internal vascularity, 7 of them with peripheral blood flow. Twelve HCNs were benign, and 3 were malignant on pathologic examination.

CONCLUSIONS

Hürthle cell neoplasms show a spectrum of sonographic appearances from predominantly hypoechoic to hyperechoic lesions and from peripheral blood flow with no internal flow to extensively vascularized lesions. Pathologic criteria differentiating benign and malignant HCNs (absence or presence of a capsular breach, vascular or extrathyroidal tissue invasion, nodal involvement, and distant metastasis) are beyond the resolution of sonography and fine-needle aspiration biopsy and require removal of the entire lesion. This precludes diagnosis and characterization of HCNs by sonography.