A CK20 positive/CK7 negative pattern has been reported to be characteristic of tumors of gastrointestinal origin.[3] Gastrointestinal adenocarcinomas secondary to MCTO most often exhibit diffuse expression of CK20 as well as negative expression of CK7.[14] It has also been documented that CDX-2, choriocapillaris and CK-20 were strongly positive and CK-7 was negative as its characteristic.[15]. Here, KRT7 is linked to multicentric carpo-tarsal osteolysis with or without nephropathy.