Sonography of Ovarian s/thecomas Patricia A. Athey, MD, Robert S. Malone, MD The sonographic findings in 14 patients with ovarian fibromas/thecomas are described. A broad spectrum of sonographic features are presented and include hypoechoic mass with posterior shadowing (two cases); anechoic mass with good through transmission (with septations, two cases; without septations, four cases), echogenic mass with well-defined posterior wall (three cases); calcified mass (two cases); mixed echogenicity mass (one case). The pattern of a hypoechoic adnexal mass with acoustic shadowing should still suggest a fibromajthecoma, but in most cases the appearance is nonspecific. KEY WORDS: ultrasonography; fibromas; thecomas; ovarian neoplasms. (J Ultrasound Med 6:431, 1987) Ovarian fibromas/thecomas are uncommon neoplasms, most frequently seen in middleaged women. Both tumors are of the same cellular origin and pathologically are difficult to distinguish from each other. Previous reports have characterized these neoplasms sonographically as hypoechoic with intense acoustic shadowing due to the fibrous component. I - 3 We present 14 cases and emphasize a broader spectrum of sonographic findings. MATERIALS AND METHODS The clinical and pathologic records and sonograms of 14 patients with surgically proven ovarian fibromas/thecomas were retrospectively reviewed. Sonography was performed with commercially available equipment utilizing a combination of static and real ~time scanning in most patients and either a 3.5- or 5-MHz transducer. Uncomplicated surgical resection was performed in each case. Histologic examination of the tumor revealed purely fibrous tissue in nine cases; Received November 3, 1986, from the Department of Radiology, Baylor College of Medicine and Ben Taub General Hospital, Houston. Texas. Revised manuscript accepted for publication March 3, 1987. Address correspondence and reprint reque5ts to Dr. Athey: Dept. of Radiology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030. fibrous tissue containing small islands of stromal cells (fibrothecoma) in four; and one tumor consisting mainly of stromal cells (thecoma). RESULTS The findings are summarized in Table 1. The patients ranged in age from 13 to 63 years with a mean of 36 years. One patient was prepubertal; five were postmen ~ opausal. Pain was the most common presenting complaint (eight patients); menstrual irregularities were present in six patients. Endocrine abnormalities (virilization) were present in the only patient with a pure luteinizing thecoma. Maximum diameter of the mass ranged from 4 to 32 em, with an average diameter of 11 cm. Two masses were hypoechoic with marked posterior shadowing (Fig. 1); two neoplasms contained strong echoes with shadowing consistent with calcification, confirmed by x-ray (Fig. 2). Six masses were anechoic with good through transmission; two of these contained septations (Fig. 3), whereas four were totally anechoic (Fig. 4). Three were solid-appearing masses with a well-defined back wall; two were moderately echogenic (Fig. 5) and one was hypoechoic. One was predominantly solid with a welldefined back wall, and it contained numerous anechoic spaces of varying size (Fig. 6). Neither ascites nor pleural effusion was present in any case. 1987 by the American Institute of Ultra ound in Medicine J Ultrasound Med 6;431-436, 1987 0278~4297/87/$3.50
432 OVARIAN FIBROMAS/THECOMAS J Ultrasound M~ 6:431-436,1987 Table 1 Clinical Histories, Sonographic and Pathologic Findings Patient Age Clinical No. (yr) Bndings Size (em) 1 13 Pelvic mass 4X6 2 53 Pelvic mass 14 X 16 3 21 Amenorrhea, pain 6X6 4 23 Menometrorrhagia. pain 6X6 5 35 Menometrorrhagia, pain 8X5 6 56 Pain 5 X 5 7 43 Amenorrhea, pain 22 X 22 8 54 Pelvic mass 4 X 5 9 53 Pain 4 X 4 10 31 Menometrorrhagia, pain 7 X ]I 11 63 Pelvic mass 3 X 4 12 20 Amenorrhea 24 X 21 13 22 Pain 20 X 32 14 16 21 wk pregnant, virilization 7 X 6 Sonography Texture Calcified Anechoic. with septations Hypoechoic, with shadow.ng Anechoic. no septations Anechoic, wuh septations Anechoic, no septalions Hypoechoic, with shadowing Calcified Anechoic, no septations Hypoechoic. good back wall Moderately echogenic, good back wall Echogenic, with muhiple anechok areas AOl.'Choic, no septations ModeraleJy echogenic, good back wall Pathology Thecoma DISCUSSION Ovarian fibromas are relatively rare, benign neoplasms, accounting for only 4% of all ovarian tumors. 4 They are classified under the sex cord - stromal tumor group, which includes thecomas, granulosa cell tumors, and Sertoli - Leydig cell tumors. Unli ke these neoplasms, fi+ bromas rarely exhibit steroid hormone production, 4 and are, therefore, frequently asymptomatic despite attaining a large size. They may become symptomatic if they undergo torsion, in which case the patient may present with an acute abdomen. s occur over a wide age range, but are most frequent during middle age. 4 They' may be a component of two unusual clinical syndromes: Meigs' syndrome, in which there are ascites and pleural effusion in associ.. tion with a fibromatous tumor of the ovary, and the basal cell nevus syndrome, which is characterized by multiple basal cell carcinomas, keratocysts of the jaw, and a variety of other abnormalities including ovarian fibromas. 4 Calcification and bilaterality in fibromas are uncommon; they are more frequently seen in tumors associated with the basal cell nevus syndrome. 4 Figure 1 Sagittal scan demonstrates large hypoechoic abdominopelvic fibroma with marked posterior shadowing.
J Ultrasound Med 6:431-436, 1987 ATHEY AND MALONE 433.. Figure 2 Transverse scan demonstrates calcified left adnexal fibroma with posterior shadowing. Note calcification anteriorly (arowheads). Figure 3 Sagittal scan of right adnexal fibroma (arrowl,eads) which is anechoic and contains thick septa.
434 OVARIAN FIBROMAS/THECOMAS J UUrasound Med 6:431-436, 1987 M-04. 0 em PRE A POST A 3. 5 Figure 4 Sagittal scan of huge. completely anechoic abdominopelvlc fibroma. Figure 5 Sagittal scan of moderately echogenic cui de sac mass which was a luteinizing thecoma... '- " 111 1..... _,. '.. _
J Ultrasound Med 6:431-436, 1987 ATHEY AND MALONE 435 Figure 6 Sagittal scan to right of midline demonstrates a mass of mixed echogenicity which was a fibroma. The gross appearance of a typical fibroma is a chalky white, hard mass that appears whorled on cut section. Marked edema and cystic degeneration are common.' Microscopically, fibromas are composed of collagenproducing spindle cells arranged in intersecting bundles. Varying amounts of intercellular edema may be present. Small amounts of lipid may be seen in the cytoplasm.' Thecomas account for less than 1% of all ovarian tumors but are considered the most common form of functioning ovarian tumor. s They are more frequent in peri menopausal and postmenopausal women. Thecomas are rarely malignant and are only occasionally associated with ascites or the Meigs' syndrome. s They generally exhibit estrogenic changes, but virilizing thecomas have been reported. S They are seldom bilateral or calcified. s Grossly thecomas are firm or rubbery in consistency and vary from white to yellow to orange in color. Edema may be present, but cyst formation is rare. s Histologically, the typical thecoma is composed of masses of oval or spindle-shaped cells with round nuclei and pale vacuolated lipid-laden cytoplasm separated by collagen forming spindle cells like those seen in fibromas. s The luteinized thecoma additionally contains scattered islands of round polyhedral cells representing theca lutein or stromal lutein cells. s The microscopic features of fibromas and thecomas may merge imperceptibly so that terms such as fibrothecoma or thecofibroma are quite common. The sonographic appearance of ovarian fibromas/thecomas has been previously described by several authors as a hypoechoic mass with marked posterior shadowing, presumably due to the dense fibrous nature of the tumor. 1-3 Calcified fibromas have also been reported. 6 Only a single case report has called exception to the above patterns by describing a cystic adnexal mass. 7 In our series, the pattern of hypoechogenicity and shadowing accounted for only two cases (14%). Two other masses were heavily calcified. More commonly the masses were anechoic or of mixed echogenicity. This can be explained by the known tendency for edema and cystic degeneration within fibromas. No significant sonographic differences could be seen in the appearance of those masses with purely fibrous tissue vs. those with scattered thecal elements. In summary, our findings indicate that the sonographic spectrum of ovarian fibromas/thecomas is wider than previously reported. Given the overlap of sonographic appearance with more common ovarian neoplasms and with ovarian cysts, definitive preoperative diagnosis is probably not possible in most cases. Nevertheless, the pattern of a hypoechoic mass with posterior shadowing seems to be fairly reliable for fibroma with the major differential being a pedunculated fibroid. REFERENCES 1. Yaghoobian J, Pinck RL: Ultrasound findings in thecoma of the ovary. J Clin Ultrasound 11:91, 1983 2 Diakoumakis E, Vieux U, Seife B: Sonographic demonstra-
436 OVARIAN FIBROMAS/THECOMAS J Ultrasound Med 6:431-436, 1987 tion of thlkoma: Report of two cases. Am J Obstet Gynecol 150:787, 1984 3. Stephenson WM, Laing FC: Sonography of ovarian Iibromas. AJR 144:1239, 1985 4. Scully RE: Sex cord-stromal tumors. [II: Blaustein A (ed); Pathology of the Female Genital Tract. New York, Springer-Vedag, 1982, p 581 5. Scully RE: Tumors of the ovary and maldeveloped gonads. In; Hartmann WH, Cowan WR (eds); Atills of Tumor Pat holog ~ Ser 2, Fasc 16. Washington, D.C., Armed Forces Institute of Pathology, 1979, p 174 6. Tytle T, Rosin D: Bilateral calcified ovarian fibromas. South Med J 77:1178, 1984 7. WOO JSK, Ghosh A:. Sonographic appearance of the ovarian thecoma. Am J Obstet Gynecol 152:361, 1985