[Iodine 131 uptake by a bronchogenic cyst in a patient with differentiated carcinoma of the thyroid gland].
BACKGROUND
After thyroidectomy for differentiated thyroid carcinoma, extracervical uptake of iodine 131 is suggestive of metastasic dissemination. False positives can however occur.


METHODS
Differentiated thyroid carcinoma was found in a female patient with a non-functional nodule. Two years after subtotal thyroidectomy and an ablative dose of iodine 131, the whole body scan showed abdominal mediastinal uptake with low serum thyroglobulin level. Considering the possibility of tumor recurrence or lymph node metastasis, the mass was excised. The histology diagnosis was mediastinal bronchogenic cyst.


CONCLUSIONS
To date, iodine uptake in a bronchogenic cyst has not been reported among other false-positives previously described. The pathophysiology of this iodine 131 uptake in a bronchogenic cyst is still unknown: the presence of NIS symporter or a protein which can organify iodine in the mucus cells of the cyst remains to be proven.
Service de Médecine nucléaire, Hôpital Cochin, Paris.
M
M
Lejeune
C
C
Héron
F
F
Tenenbaum
P O
PO
Sarfati
A
A
Louvel
J P
JP
Luton
B
B
Richard
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000601:surgery; D000293:Adolescent; D001994:Bronchogenic Cyst / Q000000981:diagnostic imaging* / Q000601:surgery; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes; D008207:Lymphatic Metastasis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000601:surgery; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D012086:Reoperation; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D013965:Thyroidectomy; D014915:Whole-Body Counting
D007457:Iodine Radioisotopes