Radiology Teaching Files > Case 865721

never visited DERMOID CYST
Contributed by: Marella Abrahamian, RT(R), Radiology Technologist, Triton College, Illinois, USA.
Patient: 30 year old female
History: A 30 year old female came in for a pelvic ultrasound for left sided pelvic pain. A transabdominal and transvaginal ultrasound was performed to determine the cause.

Fig. 1: Uterus transverse---dermoid cyst posterior to uterus

Fig. 2: Uterus transverse---shadowing from the dermoid cyst

Fig. 3: Uterus transverse---echogenic focus within the dermoid cyst

Fig. 4: Uterus transverse

The uterus measures 7.8 X 6.0 X 4.2CM. The uterus is grossly normal in appearance with no masses or fibroids.

The endometrial stripe is normal in thickness and appearance measuring 9.5MM, which is normal for a menstruating female.

The right ovary measures 3.2 X 1.9 X 1.7CM. Normal arterial and venous waveforms identified in the right ovary with no evidence of torsion.

The left ovary measures 3.3 X 2.9 X 2.3CM. Normal arterial and venous waveforms identified in the left ovary with no evidence of torsion. Posterior to the left portion of the uterus, there is a sonolucent structure which contains a hyperechoic, partially shadowing nodule. This appears to be adjacent to the left ovary and may represent a small dermoid. This measures approximately 2.1 X 1.9 X 1.8CM. Hyperechoic focus measures approximately 7.9 X 5.3 X 3.9MM.

Trace free fluid is seen within the posterior cul-de-sac.


The hypoechoic cystic structure adjacent to the left ovary which contains a central area of increased echogenicity may represent a periovarian left adnexal dermoid.


A dermoid is a common benign tumor ( making up about 10 percent of benign ovarian tumors ). A dermoid tumor develops from a germ cell ( a primary oocyte ) that is retained within the egg sac ( ovary ). The tumor develops when an egg begins developing without being fertilized.

The growing egg develops hair, teeth, cartilage, and fatty sebaceous material.

The dermoid tumor is unilateral, rount to oval mass, and the size ranging small to 40CM.

The incidence of occurrence is high in childbearing age females accounting for 80 percent of the cases.


Textbook of Diagnostic Ultrasonography
Fifth Edition/Volume2
Sandra Hagen-Ansert
Copyright 2001 by Mosby, Inc.

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Additional Details:

Case Number: 865721Last Updated: 11-26-2004
Anatomy: Other   Pathology: Benign Mass, Cyst
Modality: USExam Date: 10-05-2004Access Level: Readable by all users
Keywords: dermoid cyst

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