Details
Right breast ultrasound-guided core biopsy of 1.5 cm mass.
“Pleomorphic lobular carcinoma” refers to a variant of invasive lobular carcinoma that has increased cellular atypia and a higher mitotic rate. In classical invasive lobular carcinoma, there is wide infiltration but limited genomic complexity, with a focal loss-of-function (or promoter hypermethylation) of the cell adhesion molecule, e-cadherin. Pleomorphic lobular carcinoma may be an exception, where the tumour cells exhibit marked nuclear pleomorphism. The distinction between lobular and ductal carcinoma can be even more challenging in cases of pleomorphic lobular carcinoma.
A wide variety of practice is seen among pathologists. This case was signed out as “Invasive mammary carcinoma” with pending immunohistochemistry. Addendum then confirmed the diagnosis with E-cadherin negativity (see related content). A small focus of in situ lobular carcinoma (LCIS) is also helpful.
This biopsy also identified a focus of lympho-vascular invasion, a finding particularly helpful in a biopsy setting. A prudent surgeon would be especially attentive to the lymph nodes in this context.
This slide shows H&E stain. See related content for E-cadherin stain.
Details
Right breast ultrasound-guided core biopsy of 1.5 cm mass.
“Pleomorphic lobular carcinoma” refers to a variant of invasive lobular carcinoma that has increased cellular atypia and a higher mitotic rate. In classical invasive lobular carcinoma, there is wide infiltration but limited genomic complexity, with a focal loss-of-function (or promoter hypermethylation) of the cell adhesion molecule, e-cadherin. Pleomorphic lobular carcinoma may be an exception, where the tumour cells exhibit marked nuclear pleomorphism. The distinction between lobular and ductal carcinoma can be even more challenging in cases of pleomorphic lobular carcinoma.
A wide variety of practice is seen among pathologists. This case was signed out as “Invasive mammary carcinoma” with pending immunohistochemistry. Addendum then confirmed the diagnosis with E-cadherin negativity (see related content). A small focus of in situ lobular carcinoma (LCIS) is also helpful.
This biopsy also identified a focus of lympho-vascular invasion, a finding particularly helpful in a biopsy setting. A prudent surgeon would be especially attentive to the lymph nodes in this context.
This slide shows E-cadherin stain. See related content for H&E stain.