Mammographically Occult Invasive Lobular Carcinoma With Intradermal Invasion.

While shortcomings in the detection of invasive lobular carcinoma (ILC) continue to be studied, research is ongoing to determine detection rates using current breast imaging modalities in combination with physical examination findings. In the following case report, we describe the rare presentation of a patient diagnosed by punch biopsy with grade III, estrogen receptor (ER)-/progesterone receptor (PR)-positive invasive lobular carcinoma with intradermal invasion. This patient presented with findings similar to inflammatory breast cancer (IBC) including pain in the left nipple, skin warmth, and erythema circumferentially encompassing approximately two-thirds of the left breast. This case study is of significance as, to date, it is the first report of an invasive lobular carcinoma that presented clinically as inflammatory breast cancer and was occult on both diagnostic mammography and ultrasound. While imaging remains the primary method of breast cancer detection, it is important to note that clinical findings of dermal invasion of the breast may prompt further investigation with a biopsy and close follow-up, regardless of imaging results.