We present
a new diagnostic approach in the evaluation of difficult female pelvic
masses, especially those causing mass effect on the urinary tract.
A 35-year-old female patient presenting with pelvic pain was investigated
with Ultrasonography (USG), Computed Tomography (CT) and Magnetic
Resonance Urography (MRU). It was found that MRU, with its dual advantage
scored over both USG and CT in diagnostic accuracy. Endometriomas
diagnosed at MRU were later retrieved at surgery and proved at histopathology.
Introduction
MRI is a well established diagnostic modality for assessment of pathologies
and masses of the female pelvis. The use of MR urography as a technique
to evaluate these masses and their effects on the surrounding pelvic
organs is relatively new and is gaining widespread acceptance due
to its dual advantage. We present here a unique case in which MRU
proved its superiority over other diagnostic modalities.
Case Report
A 35-year-old female patient, Gravida 3, Para 2, Living 2, Abortion
1, presented with dull aching chronic pain in the right iliac fossa
(RIF) since two months along with weight loss, dysmenorrhoea and oligomenorrhoea.
She also complained of urgency and a sensation of incomplete micturition.
Physical examination revealed tenderness in RIF. Per vaginal examination
revealed an anteverted uterus deviated towards the left with a mass
felt in the right fornix, which was firm, immobile and tender. Routine
investigations were normal.
 |
Fig.
1 : Pelvic sonogram showing a hypoechoic lesion with
low-level internal echoes, an echogenic mural nodule (upper arrow)
and a thick echogenic wall (lower arrow).
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US examination
(Fig. 1) showed a large, eight centimeter sized cystic mass lesion
arising from the right ovary with a few mural nodules and septations
at the periphery. Mural nodules measured 5-10 mm in size and the cystic
component showed moderate-level internal echoes with mild tenderness
suggestive of haemorrhage. The lesion appeared to be adherent to the
ovary rather than arising from it. There was evidence of another 2.5
cm sized oval lesion with thick walls in the left adnexa. The pelvicalyceal
system and ureter were dilated up to the level of the right adnexal
mass. Mild free fluid was noted in pouch of Douglas (POD).
Contrast-enhanced CT scan (Fig. 2) revealed an 8 cm sized cystic lesion
with enhancing walls and septae within the lesion arising from the
right ovary. The posterior wall of the lesion was thick and irregular,
with surrounding fat stranding. Few follicles were noted in the part
of the ovary visualized just above the lesion. This lesion was causing
mass effect on the bladder (postero-superior aspect) and right ureter
with resultant moderate dilatation of right pelvicalyceal system and
ureter. Another 4 cm sized similar cystic lesion with thick enhancing
walls was noted in the POD, separate from the ovaries. Minimal free
fluid was present in the POD. Possibilities included cystic malignant
ovarian lesions or cystic lesions of infective etiology. Ca 125 levels,
however, were normal.
To further characterize this lesion, Magnetic Resonance Urography
(MRU, Figs. 3, 4) was performed after intravenous administration of
contrast (low dose i.e. 0.01 mg/kg body weight of gadolinium DTPA)
using two-dimensional Fast Low-Angle Shot (2D FLASH) T1-weighted (T1W)
coronal sequences at every one minute interval for ten minutes followed
by T2W Turbo Spin Echo (TSE) and Fast Imaging in Steady state Precession
(FISP) coronal sequences for the ureters and the bladder. A heavily
T2 weighted sequence, RARE (Rapid Acquisition with Relaxation Enhancement)
was also obtained to obtain static MRU images. Multiple cystic lesions
were seen in the pelvis showing heterogenous signal intensities, the
largest on the right, appearing hypointense on the FISP coronal images.
The right ureter was compressed by this lesion with proximal hydroureteronephrosis.
Both kidneys showed prompt excretion of contrast and good function
with a normal left kidney and ureter. The possibility of endometriosis
was strongly considered due to heterogenous signal intensities seen
within the lesion on MRU, suggestive of blood products in various
stages of degradation.
Fig.
2 : Contrast-enhanced CT. Hypodense right ovarian lesion
with a thick enhancing wall and a hyperdense enhancing mural nodule.
Fig. 4 : T2 weighted post-contrast MR Urogram
depicting a dilated right pelvicalyceal system and ureter, the
lower third of which was compressed by the pelvic lesions. |
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Fig.
3 : T1 weighted pre-contrast MR Urogram depicting heterogenous
signal intensity lesions in the pelvis with thick, high signal
intensity walls.
Fig. 5 : Post-operative specimen depicting thickened
fibrotic walls and irregular, necrotic inner surfaces. |
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At surgery, two
masses were removed. Grossly, they were brownish externally with thickened
fibrotic walls and irregular, necrotic inner surfaces (Fig. 5). The
diagnosis of endometriosis was confirmed pathologically.
Discussion
Endometriosis is the appearance or occurrence of active endometrial
tissue at sites other than the endometrial cavity, relatively frequent
in females of menstrual age.
Endometriomas have a broad spectrum of sonographic patterns due to
evolutionary blood degradation processes. They can be anechoic to
hypoechoic adnexal masses with low-level internal echoes having hyperechoic
wall foci and wall nodularity with acoustic enhancement. They can
also appear to be multiloculated cystic masses with poor vascularity.
They present with a diagnostic dilemma as they simulate the appearance
of haemorrhagic ovarian cysts, tubo-ovarian abscesses, cystadenomas,
cystadenocarcinomas or even cystic teratomas.1-4 Haemorrhagic
cysts are discovered because intracystic haemorrhage is acutely symptomatic
and shows fibrinous strands and retracting clots whereas endometriomas
are persistent lesions and are rarely seen with fresh haemorrhage.
A mass with low-level internal echoes, hyperechoic wall foci, without
neoplastic features and with multilocularity is 64 times more likely
to represent an endometrioma than another adnexal mass.2
The hyperechoic wall foci may contain cholesterol, perhaps from the
breakdown of cell membranes. Despite the considerable overlap in the
morphologic patterns of different pelvic masses, a characteristic
sonographic appearance frequently allows at least a narrow differential
diagnosis, particularly when imaging findings are coupled with sufficient
clinical data.3, 5
The finding of hyperdense foci on CT (attenuation: 90 - 140 Hounsfield
Units) next to the inner border of the lesion is suggestive of endometrioma
and should help in distinguishing from other pelvic masses. CT allows
identification of the extent and relationship of the mass to the neighbouring
structures. Discrete adnexal endometriosis appears as thick walled
cystic masses or as simple cyst(s). CT plays an important role in
demonstrating bowel wall involvement and pelvic side-wall lesions.6
MRI is a very promising modality for the evaluation of the female
pelvis and unlike CT, carries no radiation burden for the patient.
MRU, a technical modification evaluates the proximal urinary tract
in addition. Some workers have recommended the use of protocols which
include T1W sequences with fat suppression and/or without contrast
administration.7 High accuracy is obtained due to multiplanar
imaging and the ability to detect blood degradation products. It also
provides information about site and size of extra-peritoneal lesions.8
For our patient we ran T1W sequences (FLASH) with non-nephrotoxic
gadolinium as contrast (to gauge renal function) and T2W sequences
(TSE, FISP) including a heavily weighted T2 sequence (RARE). This
afforded excellent functional-anatomical correlation as regards renal
status at the same time providing sufficient pathological information.
Conclusion
Judging by careful correlation between the surgical and pathologic
specimens and radiological investigations, we found US to be extremely
accurate in determining the size, shape and location of the endometriomas.
However, we had to strongly rely upon MR urography to characterize
these pelvic masses and to gain an insight into the secondary obstructive
effects they were producing on the urinary tract. In addition, MRU
with its large field of view proved useful to corroborate the ultrasound
findings and to completely replace CT in such patients. We thus recommend
this technique (MR urography) in such problem cases where ultrasound
is unable to provide complete answers and CT adds no conclusive diagnostic
information.
References
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diagnostic performance of US. Radiology 2000; 215(1): 305-7.
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pelvic masses: sonographic spectrum. Radiographics 1996; 16(2): 321-34.
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7. L. Manganaro, L. Ballesio, E. Notarianni, C. De Felice, C. Andreoli;
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correlations. ECR 2001, Presentation C-0368.
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CORTICOSTEROID
INJECTION IMPROVES KNEE PAIN
Intra-articular corticosteroid injections improve symptoms of
osteoarthritis of the knee in the short term, and may work even
after six months. Arrol and Goodyear-Smith reviewed 10 randomised
trials and found that intra-articular steroid injections improved
symptoms at one to two weeks (relative risk 1.66). Only one
study of good quality had results at 16-24 weeks; it showed
a benefit from treatment. No major harms were found, and the
only study investigating potential loss of joint space found
no harm after steroid injection. Higher doses of corticosteroids
may be needed to obtain long term benefits, the authors say.
BMJ, 2004; 328 : 869. |
