Добавил:
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Книги по МРТ КТ на английском языке / MRI and CT of the Female Pelvis Hamm B., Forstner R..pdf
Скачиваний:
4
Добавлен:
05.10.2023
Размер:
41.73 Mб
Скачать

260

A. Schlattau et al.

 

 

large, are predominantly solid or cystic and solid, and contain only few foci of fat (Heifetz et al. 1998).

4.2.3.2\ Monodermal Teratoma

Monodermal teratomas are composed mainly of one tissue type. They include struma ovarii, ovarian carcinoid tumors, and tumors with neural differentiation.

Struma ovarii is the most common type and accounts for 3% of all mature teratomas (Matsuki M 2000). It consists predominantly or solely of mature thyroid tissue. A mixed morphology with acini filled with thyroid colloid, hemorrhage, fibrosis, and necrosis is found. Rarely struma ovarii may produce thyrotoxicosis.

Carcinoid tumors are frequently associated with a mature cystic teratoma or a mucinous ovarian tumor. Unlike most cystic teratomas, they are predominantly found in postmenopausal women. The

course is usually benign; there is a small subset of carcinoid tumors and of struma ovarii that are malignant. Carcinoid syndrome is uncommon.

Imaging Findings

On CT and MRI, a struma ovarii displays as a heterogeneous complex mass (Fig. 23). They present as cystic lesions or with a multilocular appearance with loculi displaying high signal intensity on T1 and T2, some with low signal intensity on T1and T2-weighted images on MR. Fat is not seen in struma ovarii. Carcinoid tumors are solid tumors indistinguishable from solid ovarian malignancies.

4.2.4\ Benign Sex Cord-Stromal Tumors

Sex cord-stromal tumors include neoplasms that are composed of granulosa cells, theca cells, and their luteinized derivates, including Sertoli cells,

a

b

c

d

e

Fig. 23  Struma ovarii in a 49-year-old patient. (a) Sagittal T2-weighted image; (b) axial T2-weighted image; (c) axial T1-weighted image; (d) axial T2-weighted image; (e) axial fat-suppressed gadolinium-enhanced T1-weighted image. T1and T2-weighted images show a multiloculated cystic mass in the right ovary, with locules

of variable signal intensity. There are locules showing high signal both on T1and T2-weighted images and low signal fat-suppressed gadolinium-enhanced T1-weighted images that are consistent with fat (arrows). Note the typical locules with low T2-weighted signal due to the presence of colloid content (dashed arrows)