Diagnostic ultrasound ( PDFDrive )

CHAPTER 16 The Adnexa 583
U
A B C
D E F
G H I
FIG. 16.19 Dermoid Cysts: Spectrum of Appearances. (A) Small, highly echogenic mass in an otherwise normal ovary. (B) Transverse TAS
shows the uterus (U). In the right adnexal region, there is a highly echogenic and attenuating mass (arrows), the “tip of the iceberg” sign. (C)
Highly echogenic intraovarian mass with no normal ovarian tissue. (D) Mass of varying echogenicity with hair-luid level (straight arrow) and highly
echogenic, fat-containing dermoid plug (curved arrow) with shadowing. (E) Mass with fat-luid level (arrow), with dependent layer more echogenic.
(F) Mass containing uniform echoes, small cystic area, and calciication (arrows) with shadowing. (G) Combination of dermoid mesh and dermoid
plug appearances. (H) Dermoid mesh, multiple linear hyperechogenic interfaces (lines and dots) loating within cystic mass. (I) Multiple mobile
spherical echogenic structures loating in a large, cystic pelvic mass.
the nondependent layer will be more echogenic. 169 Another rare
but characteristic feature is multiple mobile spherical echogenic
structures loating in a large, cystic pelvic mass 170 (Fig. 16.19I).
hese spheres are typically composed of desquamative keratincontaining
ibrin, hemosiderin, and hair.
Patel et al. 171 found that an adnexal mass showing two or
more characteristic sonographic dermoid features had a positive
predictive value of 100%. Pitfalls in the diagnosis of cystic teratomas
have been described. 172 Acute hemorrhage into an ovarian
cyst or an endometrioma may be so echogenic that it resembles
a dermoid plug. However, posterior sound enhancement is usually
seen with acute hemorrhage, whereas the dermoid plug tends
to attenuate sound. Other pitfalls include pedunculated ibroids,
especially lipoleiomyomas, and perforated appendicitis with an
appendicolith. An echogenic dermoid may appear similar to
bowel gas and may be overlooked. If a deinite pelvic mass is
clinically palpable and the sonogram appears normal, the patient
should be reexamined, to carefully assess for a dermoid.