Occult inflammatory breast cancer: review of clinical, mammographic, US and pathologic signs

PURPOSE:To examine the clinical, radiologic and pathologic findings of occult inflammatory breast cancer (OIBC) in order to identify features useful for diagnosis.MATERIALS AND METHODS:We retrospectively reviewed the records of 19 women with OIBC observed at our Department between 1992 and 2001. We analysed the clinical history, mammographic, ultrasonographic, and pathologic findings and investigated overall survival (OS), prognostic variables and radio-pathologic correlations.RESULTS:The most common mammographic findings were: diffusely increased density (52.63%), trabecular thickening (42.1%), mass (36.84%). The most common US findings were axillary lymphadenopathy (68.75%), skin thickening (43.75%) and mass (56.25%). At least one inflammatory sign was found in 14 women (74%) at mammography (subcutaneous thickening, trabecular thickening, diffuse increase in density) or at US (subcutaneous thickening, diffuse increase in echogenicity due to oedema, lymph vessel dilatation). Estrogen receptors (ER) were present in 63.2% and Progesterone receptors (PgR) in 36.8%. Significant prognostic variables were ER and Ki 67.CONCLUSIONS:The typical radiological pattern of clinical inflammatory breast carcinoma is less frequently present in OIBC; nevertheless the radiologist must pay attention because frequently OIBC presents just one radiological sign and this should be enough for a diagnostic suspicion. Moreover, the absence of clinical and radiological inflammatory signs does not exclude inflammatory breast cancer because OIBC can manifest at imaging as a mass or isolated calcifications. ER and PgR are positive in a high percentage of patients and confirm that OIBC has a better prognosis than clinical inflammatory breast cancer.