Case 34: Pelvic pain

 

Case 34: Pelvic pain

CASE 34: PELVIC PAIN

History

A 27-year-old woman complains of left iliac fossa pain. The pain started while she was asleep

the night before last and she says it woke her suddenly. Initially the pain was constant and

severe and she was unable to get out of bed for a few hours. She felt nauseated and did not eat

anything all day yesterday. There was no associated bleeding or discharge and there are no

bowel or urinary symptoms. Today the pain is still present but much improved and she has

been able to have breakfast.

She has had similar episodes twice in the past but they were not as severe or long lasting. She

had never been pregnant and uses the progesterone only pill (POP) for contraception. She has

been with her partner for 3 years and has not had any previous sexually transmitted infections. There is no other medical history of note.

Examination

The temperature is 37.1°C, heart rate 76/min and blood pressure 122/70 mmHg. The abdomen is slightly distended and tender in the suprapubic and left iliac fossa regions with some

rebound tenderness but no guarding. No masses are palpable. Speculum examination is normal and she is tender in the left adnexa on bimanual examination, but no cervical excitation

or masses are evident.

INVESTIGATIONS

Normal range

Haemoglobin 12.3 g/dL 11.7–15.7 g/dL

White cell count 7.1×109/L 3.5–11×109/L

Platelets 402×109/L 150–440×109/L

C-reactive protein 2.5 mg/L <5 mg/L

Urinary pregnancy test: negative

Urinalysis:

Protein: trace

Blood: negative

Leucocytes: negative

Nitrites: negative

Transvaginal ultrasound report: the uterus is anteverted and normal size. The endometrium is thin and measures 3.1 mm. Both ovaries appear normal. There is a moderate

amount of anechoic free fluid in the pouch of Douglas, measuring 30×26×15 mm.

Questions

• What is the differential diagnosis?

• How would you manage this patient?100 Cases in Obstetrics and Gynaecology

84

ANSWER 34

The sudden onset of left iliac pain suggests rupture, haemorrhage or torsion of an ovarian

cyst. In cases of torsion of the ovary this would normally result in vomiting and systemic

upset, whereas this woman’s condition has in fact improved. In addition, an adnexal mass

would be visible on ultrasound. Haemorrhage into a cyst would be seen on transvaginal

ultrasound scan as an echogenic ovarian enlargement.

If a cyst ruptures then it is common for the ovary to appear ultrasonographically normal

afterwards but the finding of free fluid in the pouch of Douglas suggests this pathology.

Thus the diagnosis is likely to be a ruptured ovarian cyst. Alternative diagnoses may include

irritable bowel syndrome or possibly renal colic, though urinalysis does not show haematuria.

Management

The patient is already improving and the free fluid which is causing the peritoneal irritation (and the rebound tenderness) is expected to resolve spontaneously. Therefore immediate

management is supportive with analgesia.

In the longer term, the woman should be advised to use a different contraceptive as the POP

is known to be associated with an increased incidence of ovarian cysts and it seems from the

history that this is the third episode for this woman.

KEY POINTS

• The only ultrasound evidence of ovarian cyst rupture may be the presence of free

peritoneal fluid.

• Ovarian cyst rupture should be managed expectantly.

• An increased incidence of ovarian cysts is found in women using the progesterone

only pill, whereas the combined oral contraceptive pill reduces cyst occurrence by

inhibiting ovulation.