A 52-year-old lady presented to clinic complaining of pelvic pain. She underwent ultrasound examination which identified a 9cm echogenic mass within the lower abdomen/pelvis, the exact origin of which was uncertain. Computed tomography (CT) scan of the abdomen and pelvis was recommended, selected images of which are shown in Panel A (Axial CT image) and B (Sagittal CT image). Q: What is the diagnosis? Answer: refer to page 57

(Refer to page 35) Answer: Ovarian dermoid cyst (Mature cystic teratoma) An ovarian dermoid cyst (mature cystic teratoma) is a congenital benign germ cell tumour that contains tissues derived from all three germ cells layers (ecto, endo and mesoderms), but with a predominance of ectodermal components. These cysts may contain hair, skin, epithelium, fat and teeth. Dermoid cysts can occur elsewhere in the body, such as the orbit, spine and neck. They occur most commonly in the reproductive years, and usually present with either chronic pelvic pain, a palpable mass or less commonly with acute pain due to torsion or intratumoural haemorrhage. Although torsion is the most common complication, cysts may also rupture and rarely undergo malignant change developing into squamous cell carcinomas.

A middle aged female presented to the Department of Obstetrics and Gynaecology complaining of lower abdomen swelling, which had been present for over a year, but getting progressively bigger over time. Ultrasound imaging confirmed the presence of a pelvic mass and imaging on multislice computed tomography (MSCT) are shown above: Coronal (Panel A) and Sagittal (Panel B) planes. Surgery was performed. What is the diagnosis? Answer: refer to page 58

Refer to page 36) Answer: Massive uterine fibroid Uterine fibroids (leiomyomas of the uterus) are extremely common, typically measuring 2cm to 5cm in size. Fibroids may be either solitary or multiple, with presenting complaints of subfertility, dysmenorrhoea, menorrhagia or pelvic pain. Uterine fibroids are benign tumours that arise from the overgrowth of smooth muscle and connective tissue. Histologically, a monoclonal proliferation of smooth muscle cells gives rise to these tumours, which can be hugely variable in size. Uterine fibroids occur twice as frequently in black women as in either white or Asian women and can occur at any time between menarche and menopause, but are most common in women 35 to 49 years of age. 1 Fibroids typically resolve after menopause. Rarely, uterine fibroids may undergo malignant degeneration to become sarcomatous, but this is the exception. The incidence of malignant degeneration is low and has been estimated to be as low as 0.2%.

A 24-year-old female with a normal body mass index was undergoing investigation for refractory hypertension. Ultrasound imaging identified a disparity in bipolar renal lengths and a subsequent renal artery Doppler suggested a velocity change in the right renal artery. Computed tomographic angiography (CTA) of the kidneys (Panel) was performed for further assessment.

An 82-year-old man presented to the Accident and Emergency department with abdominal pain and distension. He had attended previously to the surgical team with similar problems. Plain abdominal radiography is shown above (Panel). What is the diagnosis? Answer: refer to page 188

(Refer to page 166) Answer: Sigmoid Volvulus. There are three types of gastrointestinal tract volvuli: gastric, caecal and sigmoid. Sigmoid volvulus is the most common form and is responsible for eight percent of all intestinal obstructions. 1 Sigmoid volvulus is particularly common in the elderly and also psychiatric patients. Patients typically present with abdominal pain, distension, and absolute constipation. Predisposing factors to sigmoid volvulus include chronic constipation, a megacolon, and an excessively mobile colon.