lull/CASE REPORT

RADIONUCLIDE STUDY OF STRUMA OVARII

En-unYeh, RobertC. Meade, and Philip P. Ruetz Wood Veterans Administration Center, Medical College of Wisconsin, Milwaukee, Wisconsin

Modern methodology used in studies of lower pole of the left lobe. Pelvic examination re struma ovarii, including thyroidal radiolodine vealed a mass. uptake, serum 7'@and T3 resin uptake, conver The EKG revealed atrial fibrillation. IVP and sian ratio, and @@1Iand ssmTc scans of thyroid pneumogynogram suggested a pelvic tumor with and pelvis, before and after perchiorate wash calcification. A bone survey was negative. Protein out, revealed increased T4 production with T, bound iodine (PBI) was too high to read. resin uptake at the upper limit of normal due The 24-hr 1311thyroid uptake was 1% but serum to functioning thyroid tissue in a teratoma. T4 was 40 p.g% and T, resin uptake* was 39% . The These findings are compared with other re conversion ratio was 100% in 24 hr. Thyroid images ported studies in this unusual condition. with 131!and °°@[email protected] similar; both showed generally poor uptake except for a func tioning nodule in the left lower pole (Figs. 1 A and Struma ovarii is an infrequent tumor. Woodruff, B). The 24-hr 1311pelvic scan (after urinary cathe et at (1 ) found only 13 cases among 2,000 ovarian terization) showed a round area of high uptake, tumors. Kempers, et al (2) reported eight cases of about I0 cm in diam (Fig. 2) . The 24-hr uptake in struma ovarii with hyperthyroidism. Radioisotope the pelvis was 17% . The total-body scan showed studies of these cases were incomplete. There are no other abnormal uptake. The °°@Tcpelvic radio no cases reported in which the tumor was scanned before surgery or studied with o9mTc@pertechnetate. Well-documented uptake and thyroxine studies be Received May 18, 1972; revision accepted Sept. 27, 1972. For reprints contact: En-Lin Yeh, Nuclear Medicine Serv fore and after removal of the tumor are rare. This ice, Wood Veterans Administration Center, Milwaukee, Wis. paper is a report of such a case diagnosed pre-opera 53193. tively by scintiscan and evaluated pre- and post C Tetrasorb and Triosorb tests from Abbott Laboratories. The normal range for T4, 5.3—14.5,@g/100ml serum. (In operatively. A detailed clinical description will be this patient, serum was diluted 1:2 with normal saline; presented elsewhere (3). otherwise T4 was too high to read. ) The normal range for T3 resin uptake, 25—39%. CASE PRESENTATION A 64-year-old white female was first admitted to . our hospital in 197 1. Her past medical history in . . z . . . cluded a diagnosis of hypothyroidism in 1969 which ..• w . @. ..@. was treated with I grain of desiccated thyroid daily. •@; .•r@• A pelvic mass was detected at that time. Thyroid .i. @J4.J medication was continued up to this admission. She had noted some weight oss in recent months but no other thyrotoxic symptoms. @.:c@i::@.@ Physical examination on admission revealed a thin lady with irregular pulse. Slight lid lag was noted, and a fine hand tremor was present. The thyroid FIG. 1. A and B showthyroid images with 1311and @@mTc. gland was enlarged, and a nodule was felt in the pertechnetate, respectively.

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subnormal range in 6 days. The half-life of the pa .@-: tient's endogenous serum T4 was 1.6 days (Fig. 5). In spite of low T:4resin uptake and T4, the patient never had symptoms of hypothyroidism. Two weeks

-. postoperatively, the 24-hr 131! thyroid uptake, fol lowing 10 units of TSH, was 2%. Seven weeks post operatively, the T4 was 7.5 @g%, the T, resin uptake was 24% , and the 24-hr 131!uptake was 13%. @ ¶@‘ DISCUSSION @* When this patient was first found to have a low @—... 4 181! thyroid uptake and high PB!, T3 resin uptake and T4, it was more than 1 month after she discon tinued taking 1 grain of desiccated thyroid daily which she had taken for 2 years. According to John FIG.2. Radioiodin.pelvicscansuperimposedon IVPølm. ston, et al (4), in a euthyroid patient taking up to 2 grains of thyroid daily for longer than 6 months, @ f:— the BMR and PB! are usually within normal limits. On discontinuation, the PB! reaches its lowest level in 1—3weeks and then rises gradually to normal levels in 1—2months. Therefore the exogenous thy roid therapy failed to explain the abnormal thyroid studies and an endogenous ectopic thyroid source was considered. With the physical finding of a pelvic mass and low uptake in the thyroid, the 131! pelvis

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FIG. 3. A, B, and C are @°mTc-pertechnetatepelvicradionu clide angiograms. D and E are pelvic images 1 mm and 30 mm after injection, respectively. F is 60-mm image (30 mm after KClO4 administration).

nuclide angiogram disclosed that the right iliac artery was displaced laterally with an area of high per fusion, medial to the right iliac artery, imaged in the pelvis (Figs. 3 A—C). The 30-mm pelvic image showed little increase in uptake compared with the 1-mm image (Figs. 3 E and D, respectively). Potas sium perchlorate (800 mg) was given by mouth immediately after the 30-mm study. Thirty minutes later the pelvic image seemed to show little washout ,—.. I of 9OmTc(Fig. 3 F). The patient subsequently developed abdominal pain, and at emergency laparotomy a twisted right ovarian tumor ( 10 cm in diam) was removed. The @ gross appearance and in vitro 1311 scan (9 days - J'I@ ‘@‘@L. I after 1311administration) of the removed tumor are I shown in Fig. 4. Pathologically the tumor was an infarcted teratoma composed mostly of active thy ‘@ . roid tissue. The 24-hr 1311pelvic scan after operation showed no abnormal uptake. FIG. 4. Gross appearance (upper) and ‘@lscan (lower) of Postoperatively, serum T4 decreased rapidly to a removedovarian tumor.

Volume 14, Number 2 119 YEH, MEADE, AND RUETZ

50- the result of 131! studies was not mentioned in the 40- article. Discrepancy between studies on thyroid car 30' cinoma with 125! and O9mTc has been found. Stein berg, et at (10) reported a case of primary thyroid T-@@2-l.6 DAYS carcinoma which was hot on the oDmTcscan but cold 1-4 20' on the radioautograph 3 days after 125Jadministra )Lg% tion. It was explained that the tumor may be intact to trap O9mTc and presumably 125! but not differen l0@ 9, tiated well enough to organify 125!. On the contrary, 8' 7, Meighan, et at (1 1 ) reported a failure to detect 1311 6 positive thyroid metastasis with 99mTc. The metas 5. tases were in the upper mediastinum and the failure 4. . was attributed to the high vascular background. In 3, our case the discrepancy between the high 131!up take and relatively low 99mTc uptake in the ovarian 2 thyroid tissue may be partly due to high vascularity

I of the tumor as shown in the radionuclide angiogram and high background in the pelvis. Studies on struma

@ 0' @‘ @, @‘ ovarii with @@mTchave not been previously reported. Ramagopal, et al (12) reported a case of struma DAYS POST-OP ovarii containing most of the iodine in the form of monoiodothyronine. In our case, after removal of F1G.5. Endogenousserum1, clearanceafterremovalof struma the tumor the serum T4 decreased rapidly from 40 ovarii. /Lg% to subnormal range, proving that the tumor was scan was made which showed an area of high uptake indeed the major source of T4 production. The en in the tumor. dogenous serum T4 disappearance curve after re The OOmTcpelvic radionuclide angiogram showed moval of the tumor shows a half-life of 1.6 days. a tumor stain from the right iliac artery which was Normal endogenous T4 disappearance rates could displaced laterally. Thirty minutes after oomTc in not be found in the literature. Compared with the jection, the uptake in the tumor area increased very exogenous radiothyroxine disappearance studies of little. Potassium perchiorate seemed to wash out Sterling, this patient was markedly hypermetabolic little of the O9mTcfrom the tumor in 30 mm. Andros, (13). et al (5) studied thyroid 99mTc uptake from the It is interesting that this patient never exhibited difference before and after perchlorate washout and symptoms of hypothyroidism even when T4 was 0.9 found the result to agree closely with the uptake @Lg%. In a case of struma ovarii reported by Pert calculated by quantitating the thyroid dot scan di mutter, et al (14) following removal of the tumor, rectty. However, in rats Papadopoutos, et a! (6) the PB! became subnormal in a week, but the BMR found evidence that 99mTcis metabolized in the thy was always well within normal limits. Perhaps tissue roid gland. But the evidence did not seem valid T4 and T, were still adequate to sustain a normal for the thyroid studies within a few hours after BMR even when serum T4 was well below normal 9OmTc injection. If OOmTc is organified by the thyroid limits soon after removal of the struma ovarii. gland, it would not be expected to be washed out Two weeks postoperatively, when T4 was tow, by perchlorate. Observing perchlorate washout in a TSH stimulation was made with a single dose (10 humans, Shimmins, et at (7) found that 99mTc@per@units) of TSH. The 131! uptake showed no significant technetate was not significantly bound in the thyroid response. However, 7 weeks postoperatively, T3 gland up to 3 hr after administration. In our case resin uptake, T4, and T7 returned spontaneously to little 9OmTcwas discharged by perchtorate from the normal ranges. Primary hypothyroidism can there tumor 1 hr after o9mTcadministration. Unfortunately, fore be ruled out and the result of the TSH test is quantitative studies were not done in this case to apparently false. In the literature a lack of standard give an absolute uptake of 99mTc in the tumor before ization in the methods and interpretations of the and after perchiorate washout. TSH is evident. In a review article Fore, et at (15) Dodds, et al (8) reported two cases of lingual stated that patients who failed to respond to one thyroid detected with @@mTcscannings. But Gorow dose of TSH were never proved to respond to multi ski, et at (9) reported failure to accumulate °9@Tc pie doses. However, Taunton, et al (16) reported by lingual nodule and thyroglossal duct. However, that three doses of 5-unit TSH gave maximal stimu

120 JOURNAL OF NUCLEAR MEDICINE RADIONUCLIDE STUDY OF STRUMA OVARII

lation of ‘@‘Iuptake in secondary hypothyroidism. scanning and the study of thyroid physiology. I Clin En Three patients with long-standing Sheehan's syn docr25: 1067—1076,1965 drome showed no response although they had re 6. PAPADOPOULOS S, MACFARLANE S, HARDEN RMcG : A comparison between the handling of iodine and technetium sponded earlier. The long duration of the disease by the thyroid gland of the rat. I Endocr 38: 381—387,1967 may be an important factor responsible for the lack 7. SHIMMINS JG, HARDENRM, ALEXANDERWD: Loss of response. of pertechnetate from the human thyroid. I Nucl Med 10: In our patient the cervical thyroid gland was in 637—640.1969 active for a tong period of time due to pituitary and 8. DODDSWi, POWELL MR : Lingual thyroid scanned with mm'rc-pertechnetate. Amer I Roentgen 100: 786—791, hypothalamic suppression by the ectopic thyroid. I967 This prolonged period of inactivity may have re 9. GOROWSKIT, CH0MIcKI 0, LENARTOWSKAI : Thyroid sulted in a toss of response to TSH. Although the scanning with @mTcin children and adolescents. Nuclear TSH test is valid in most patients receiving long term medizin 9: 218—225,1970 thyroid replacement, some patients may have an 10. STEINBERGM, CAVALIERIRR, Cuoy SH : Uutake of ‘@mTc-pertechnetatein a primary thyroid carcinoma : Need impaired response to TSH for 2—3weeks after dis for caution in evaluating nodules. I Cliii Endocr 31: 81— continuing thyroid. The response then returns to 84, 1970 normal after 6—8weeks (15,17) . In our case, the 11. MEIGHANJW, DWORKIN HJ : Failure to detect ‘9 TSH test was made 2 weeks after removal of the positive thyroid metastases with @mTc.I NucI Med 11: 173— ectopic thyroid tissue, and the gland was still refrac 174, 1970 12. RAMAGOPALE, STANBURYJB: Studies of the distri tory to TSH at this time. bution of iodine and protein in a struma ovarii. I Clin Endocr25: 526—533,1965 REFERENCES 13. STERLING K, CHODOS RB: Radiothyroxine turnover studies in myxedema, thyrotoxicosis and hypermetabolism 1. WOODRUFFJD, RAuH JT, MARKLEY RL: Ovarian without endocrine disease. I Clin Invest 35: 806—813,1956 struma. Obst Gynec 27 : I94—201, I966 14. PERLMUTrERM, MUFSON M, DAVID M: Inhibition 2. KEMPERSRD. DOCKERTYMB, HOFFMAN DL, et al: of a cervical thyroid gland by a functioning struma ovarii. Struma ovarii.—ascitic, hyperthyroid, and asymptomatic I ClinEndocr11:621—629,1951 syndromes. Ann intern Med 72: 883—893, 1970 15. FORE W, WYNN J : The thyrotropin stimulation test, 3. BROWNW, SHErrY KR, ROSENFELDPS: Struma ovarii AmerJMed4O: 90—96,1966 with hyperthyroidism : Demonstration by radioiodine scm 16. TAUNTON OD, MCDANIEL HG, PITrMAN JA Stand tiscan. Ann intern Med: to be published ardization of TSH testing. I Clin Endocr 25: 266—277, 4. JOHNSTON MW, SQUIRES AH, FARQUHARSON RF: The I965 effect of prolonged administration of thyroid. Ann Intern 17. LEVY RP: Appraisal of the thyrotropin stimulation Med35: 1008—1022,1951 test and the significance of low thyroid reserve. Thyrotropin. 5. ANDROSG, HARPERPV, LATHROPKA, et al : Pertech Proceedings of a Conference on Thyrotropin. Springfield, netate-99m localization in man with applications to thyroid Ill., C C Thomas, 1963, pp 335—347

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