MP/H Rules/Multiple primaries--Breast: Does rule M10 apply in this situation?
L breast biopsy = INVASIVE DUCTAL CARCINOMA
L breast simple mastectomy = 2.0 cm INVASIVE DUCTAL CARCINOMA with an incidental finding of separate 1.0 cm INVASIVE LOBULAR CARCINOMA; pathologist specifically states the tumors are morphologically different. The tumors are both pure Ductal/pure Lobular.
Surgery of Primary Site--Pleura: How is this field coded if the patient underwent an exploratory thoracotomy with partial decortication that excised some, but not all, of the pleural mesothelioma tumors? See Discussion.
Reportability--Skin: Is this reportable? If so, what is the correct histology code? The pathology report says, " bx of 0.7 x 0.5 cm gray-pink papule on tan-pink skin of left inferior centra malar cheek revealed invasive SCC of skin, signet ring cell type, invading papillary dermis; LVI neg; "findings are diag of SCC exhibiting the rare signet ring histologic subtype"; deep margin positive for tumor but peripheral margins clear;".
MP/H/Histology--Lung: Would you code a lung primary of "non-small cell carcinoma with neuroendocrine differentiation" to non-small cell carcinoma (8046/3) or carcinoma with neuroendocrine differentiation (8574/3)? See discussion.
MP/H Rules/Multiple primaries--Colon: This is an unusual case of multifocal colon cancer. The case is staged pT4b,N1b. Per our MP rules, this will be 4 separate primaries. Would this be an exception to the rules; if not now, possibly in future versions of the MP rules for colon cancer? See discussion.