D2-40, as discussed previously, is expressed in lymphatics and PCANs, but reactivity has also been reported in the 15 CNTs thus far studied.
D2-40 is variably expressed in a wide variety of lesions, including sebaceous neoplasm, epithelioid sarcoma, AFX, SCCs, CNTs, DFs, and PCANs. ([dagger]) Expression of lymphatic markers, including Prox1 and D2-40, in angiosarcoma suggests that it may show a mixed endothelial phenotype.
Differentiation of metastatic adenocarcinomas from primary cutaneous adnexal neoplasms (PCAN), especially malignant ones, can be difficult.
Podoplanin (D2-40) expression is also a useful adjunct in differentiating adenocarcinomas that have metastasized to the skin from PCAN. Reactivity with D2-40 is seen in primary cutaneous carcinomas and skin adnexal tumors but is absent in metastatic adenocarcinomas to the skin.