Radiologic Features of IdiopathicGranulomatous MastitisZ. ACHOUR 1, H. EL MHABRECH1, A. KHELIFFI1, E. BEN SALEM1, A. HADDAD2, CH. LOUSSAIF 3, C. HAFSA1
Radiology Service, CMN Monastir Tunisia
INTRODUCTION:
Idiopathic granulomatous lobular mastitis,or
idiopathic granulomatous mastitis (IGM), is a rare
chronic inflammatory lesion of the breast that can
clinically and radiographically mimic breast
carcinoma.
purpose:
The aim of this study is to describe the radiological imaging features of IGM in order to better differentiate this disorder from breast cancer.
MATERIALS AND METHODSWe performed a retrospective analysis of the clinical
and radiographic features of 7 women with a total of
7 IGM lesions. The ages of these women ranged
between 30 and 48 years.
The chief clinical complaint was: breast mass in 4
cases and inflammatory mastitis in 3.
All patients were examined by both mammography
and sonography.
RESULTS:A 37 year-old female, gravida 6 para 3 consulted for a right breast mass A mammogram was realised and concluded to an increased density of the upper lateral quadrant of the right breast. US hypoechoic area with low decreased acoustic shadowing. The patient undrwent a surgical excision and pathology showed IGM
a
US: irregula tubular lesions
Lateral mammogram of a 34-year-old female patient with a huge idiopathic granulomatous mastitis. Note the presence of a vague increased density of the left breast in the absence of a discrete mass or suspicious micro-calcifications.
A 48 year-old female, gravida 5 para 3 consulted for a right breast mass. A mammogram was realised and concluded to an increased density of the lower lateral quadrant of the right breast. US hypoechoic mass with low decreased acoustic shadowing.
A 48 year-old female,gravida 4 para 3, was admitted to the hospital for a recurrent breast abscess. Mammography revealed an opacity of the lower medial quadrant of the right breast. US an important galactophoric ectasia with an echogenic conten. The patient undrwent a surgical excision and pathology showed IGM with multinucleated giant cell and chronic lobulitis
Malignancy was suspected in all patients and fine needle biopss was performed in all cases cofirming the diagnosis of IGM
DISCUSSION:
Idiopathic granulomatous lobular mastitis , or idiopathic
granulomatous mastitis, is a rare chronic inflammatory lesion of the
breast that can clinically and radiographically mimic breast carcinoma.
IGM was first described by Kessler and Wolloch in 1972. This disorder
is characterized by the chronic granulomatous inflammation of lobules
without caseous necrosis IGM is of unknown origin, and its diagnosis
rests on both the demonstration of a characteristic histological pattern
and the exclusion of other possible causes of granulomatous breast
lesions.
Although the exact etiology of IGM remains unclear, associations
with autoimmune disorders, oral contraceptive use, pregnancy,
hyperprolactinemia and alpha-1-antitrypsin deficiency have been
suggested. Most studies report an average age of presentation in
the third decade of life (range 11 to 83 years) with symptoms
often developing within a few years of pregnancy. Moreover,
conflicting data exists regarding the significance of oral
contraceptive use in patients diagnosed with IGM.
The diagnosis of IGM rests on the documentation of
a characteristic histologic pattern, combined with the
exclusion of other possible causes of granulomatous
lesions of the breast.
IMAGING ASPECTS:
Mammography and ultrasonography are used mainly to rule out malignancy rather than confirming the diagnosis of IGM +++.
Mammographic features ofgranulomatous mastitis
The reported mammographic features of granulomatous
mastitis are :
An asymmetric density with no distinct margin or mass
effect: asymmetric density is a non-specific
mammographic finding that could be seen in clinically
normal breasts or in other various disease types.
Irregular ill-defined masses.
Diffuse increased density. Oval obscured masses in young women with
Heterogeneously dense breast. Calcifications in rare cases. Benign-looking axillary lymph node
enlargements. Skin thickening. Patients with dense breast parenchyma may
also have negative mammograms.
US FEATURES: Multiple clustered, often contiguous, tubular
hypoechoic lesions.
Hypoechoic mass.
Tubular hypoechoic areas connecting to a mass.
Irregular lobulated masses
Parenchymal distortions without definite mass.
Unusual Us finding of a focally decreased
parenchymal echogenicity and acoustic
shadowing.
Subcutaneous fat infiltration is minimal indicating
that the findings were not acute infection
MRI ASPECTS:o The Gd-DTPA-enhanced dynamic MRI shows
that IGM is associated with progressive
enhancement, which could be smooth or irregular,
with foci showing peripheral ring shaped contrast
enhancement pattern, with delayed washout.
o Such an enhancement pattern can mimic those of
inflammatory processes, a proliferative dysplasia,
and neoplasm.
o The real value of MRI might be in saving some
patients unnecessary surgery if an inactive lesion,
such as fibrosis or fat necrosis, is present.
o Such lesions, clinically and mammographically,
resemble carcinoma, but would not produce active
MRI enhancement pattern encountered in tumoral
or inflammatory processes.
TREATMENT:o The optimal treatment for GM has yet to be established. Surgical resection of the affected tissue, with or without corticosteroid therapy, has often been the current method of treatment.o However, with these treatments, a tendency for
local recurrences and delayed wound healing
exists.
CONCLUSION:
Clinical information and radiographic features of
GM may aid in the differentiation between IGM and
early onset breast cancer. However, a histological
confirmation is still required for a positive diagnosis
and the determination of an appropriate treatment
regimen.