Figure 1
Figura 1
Clinical History
The patient presented acutely with right sided abdominal pain and swelling. She was found to have a palpable mass in her right iliac fossa.
Imaging Findings
The patient presented acutely with abdominal discomfort and swelling of 2 weeks duration. On examination, she had a palpable mass in the right iliac fossa. Blood tests were unremarkable. AXR demonstrated tooth-like calcific densities in the right iliac fossa with displacement of bowel gas away from it. CT abdomen revealed a 9x8x8cm retroperitoneal soft tissue mass in the right iliac fossa of fat density with calcified areas within it. The mass was displacing ascending colon and small bowel loops anteriorly and medially. The appearances were typical for a dermoid cyst.
The tumour was resected. Histology confirmed the diagnosis of dermoid cyst. It was lined by keratinised squamous epithelium with skin appendages. Mature fat, bone, and cartilage was also present. No immature elements were present.
The tumour was resected. Histology confirmed the diagnosis of dermoid cyst. It was lined by keratinised squamous epithelium with skin appendages. Mature fat, bone, and cartilage was also present. No immature elements were present.
Discussion
A dermoid cyst ( also referred to as a benign cystic teratoma ) is a benign tumour that contains ectodermal, mesodermal and endodermal derivatives. They have cell walls almost identical to those of skin. Adnexal skin structures such as hair follicles, sweat glands, hair, teeth or nerves can be found. Other structures such as fat, cartilage and bone fragments are also found within the tumour.
Sites for dermoid cysts include the skin of the face, scalp and neck, intracranial and spinal sites, ovaries and testis, and the anterior mediastinum. Extragonadal retroperitoneal dermoid cysts are rare, with fewer than 100 cases having been reported. Various series have reported dermoid cysts making up 1-10% of all primary retroperitoneal neoplasms.
In adults, retroperitoneal dermoid cysts present with symptoms such as abdominal pain and distention, back pain, and oedema of the lower extremities due to their mass effect. The typical patient is female and aged 15-40 years.
X-rays, CT and MRI are useful in the diagnosis of dermoid cyst. Radiographic manifestations include the presence of various mixed components such as calcification(70%), fat(60%), and hair. MRI has advantages over CT as its better tissue contrast enables it to delineate the internal components of the tumour more accurately, as well as determine the relations of the mass to adjacent organs.
The treatment of choice for retroperitoneal dermoid cysts is complete surgical excision. The main reason for this is the worsening symptoms associated with the increasing mass effect as the tumour continues to grow. Malignant change has also known to occur. For example, squamous cell carcinoma or malignant melanoma may develop from the skin components though this is rare.
Sites for dermoid cysts include the skin of the face, scalp and neck, intracranial and spinal sites, ovaries and testis, and the anterior mediastinum. Extragonadal retroperitoneal dermoid cysts are rare, with fewer than 100 cases having been reported. Various series have reported dermoid cysts making up 1-10% of all primary retroperitoneal neoplasms.
In adults, retroperitoneal dermoid cysts present with symptoms such as abdominal pain and distention, back pain, and oedema of the lower extremities due to their mass effect. The typical patient is female and aged 15-40 years.
X-rays, CT and MRI are useful in the diagnosis of dermoid cyst. Radiographic manifestations include the presence of various mixed components such as calcification(70%), fat(60%), and hair. MRI has advantages over CT as its better tissue contrast enables it to delineate the internal components of the tumour more accurately, as well as determine the relations of the mass to adjacent organs.
The treatment of choice for retroperitoneal dermoid cysts is complete surgical excision. The main reason for this is the worsening symptoms associated with the increasing mass effect as the tumour continues to grow. Malignant change has also known to occur. For example, squamous cell carcinoma or malignant melanoma may develop from the skin components though this is rare.
Differential Diagnosis List
Retroperitoneal dermoid cyst
Final Diagnosis
Retroperitoneal dermoid cyst
References
[1]
Lane RH, Stephens DH, Reiman HM.
Primary Retroperitoneal Neoplasms: CT Findings in 90 Cases with Clinical and Pathological Correlation.
AJR 152;83-89, Jan 1989. (PMID: 2535771)
Case information
| URL: | https://www.eurorad.org/case/2240 |
| DOI: | 10.1594/EURORAD/CASE.2240 |
| ISSN: | 1563-4086 |
