Pelvic dermoid cyst in a male patient

Case contributed by Talal F M Abdullah
Diagnosis almost certain


65-year-old male patient diagnosed as a case of acute cholecystitis a week ago, treated with percutaneous cholecystostomy in another institute. Presenting complaining of right upper quadrant pain and general toxic features. Tenderness noted over the right side of abdomen. CT requested to assess for possible complications.

Patient Data

Age: 65 years
Gender: Male

The percutaneous tube noted in the GB bed with dense contrast/calculi seen.

Yellow circle: ?tiny opacification over the left side of pelvis.

Percutaneous cholecystostomy tube seen in situ with GB filled with contrast/stones.

Inflammatory changes noted in the right site of mesentery and greater omentum.

Dense urine in urinary bladder; mostly excreted from the previous interventional study.

A ~5.5 x 6.0 x 7.4 cm well-defined intra-pelvic retroperitoneal mass lesion noted containing fat, soft tissue and tiny calcified focus (looks like a tooth on bone window - not shown).  It seems to arise\abutt the posterior aspect of the left seminal vesicle. It is not abutting the colon or rectum.

The sacrum and pre-sacral space are intact.

Appendicolith noted with no acute inflammatory changes.

Case Discussion

Having the three germ cell layers in a pelvic mass is pathognomoic of mature cystic teratoma (dermoid) when seen for sure in a female pelvis arising within an ovary.  Pelvic dermoids (excluding infantile Currarino triad) are extremely rare above the age of 50 (especially in men).

Given the described lesion, with the patient age of 65; it is beyond the need for anuual surveillance with alfa feto protein to monitor malignant transformation.  Torsion however, a remote complication, is still theoriticaly possible given its size.

It could be of value to monitor it with annual pelvic ultrasound to assess the size (and alfa feto protein if increase in size) and to examine/US the testes as well to screen for another germ cell tumor.

This incidental finding of male dermoid cyst is extremely rare, with only 7 cases being reported in the literature (see reference article link below).

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