Pulmonary metastases in children and young adults with differentiated thyroid cancer

Abstract

Background. The prognostic significance and optimal care of children with differentiated thyroid cancer and pulmonary metastases are not well established. Methods. Of 209 patients younger than 25 years of age who were treated at University of Texas M. D. Anderson Cancer Center between 1960 and 1990 and for whom there was sufficient information, 19 (9%) had pulmonary metastases at presentation. Results. All of these patients had regional lymphadenopathy at the time of diagnosis. All but two had intense, diffuse radioiodine uptake in the lungs; there were two false‐negative scans immediately after surgical procedure caused by competing thyroid residual. The chest radiograph (CXR) was normal in 8 of 17 (42%) patients with abnormal radioiodine scans. After therapy with radioiodine (100–499 mCi), CXR appeared normal in 7 of 9 patients with initial abnormal radiographs (within 6–75 months). Radioiodine uptake by the lungs normalized in 3 of 8 patients with initially normal radiographs, and in 3 of 9 patients with initially abnormal radiographs. There have been no deaths in these 19 patients. Conclusion. Pulmonary metastases are not uncommon in children and young adults with differentiated thyroid cancer, especially those who have regional lymphadenopathy. The lung metastases almost always concentrate radioiodine diffusely and may be associated with a normal CXR in almost half of the patients. Pulmonary metastases may be overlooked unless near total thyroidectomy is followed by total body radioiodine scan (TBS) in all children and young adults who have regional lymphadenopathy of the neck.

A prospective clinical trial to assess the efficacy of radioiodine ablation as an alternative to completion thyroidectomy in patients with differentiated thyroid cancer undergoing sub-total thyroidectomy

“…The presence of large amount of remnant thyroid tissue, which is the case after subtotal thyroidectomy, makes detection and treatment of nodal or distant metastases difficult [13,14]. High TSH levels necessary to enhance tumor 131 I uptake cannot be ordinarily achieved with a large thyroid remnant [15] and serum Thyroglobulin (Tg) measurement made under TSH stimulation, which is the most sensitive test for the detection of recurrence, is not reliable in the presence of large thyroid remnant.…”

Pediatric Thyroid Cancers: An Indian Perspective

“…Samuels reported solitary thyroid nodule in about 54% and neck nodes at presentation in about 50% patients [23].…”

“…However, PTC also frequently presents as neck nodes with or without a palpable thyroid lesion [7]. Occasionally, the only initial presentation may be of distant metastases [23].…”

Childhood thyroid cancer in Belarus, Russia, and Ukraine after Chernobyl and at present

“…This therapeutic means undoubtedly improves prognosis for pediatric patients with well-differentiated thyroid cancer (21,41,62). The criteria of efficacy are very rigorous so that complete responders should display no evidence of 131 I accumulation on whole body scanning and have serum thyroglobulin levels < 1 ng/l.…”