Images below are from a 60-year-old woman with an 8 cm retroperitoneal mass.

	Nooshin Karamzadeh Dashti, M.D. Fellow, Surgical Pathology Mayo Clinic
	Taofic Mounajjed, M.D. Consultant, Anatomic Pathology Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 68-year-old woman underwent endometrial biopsy for post-menopausal bleeding, which showed endometrial adenocarcinoma, endometrioid type. The screening test for Lynch syndrome by IHC (dMMR-IHC) and molecular testing for microsatellite instability (MSI testing) was performed, and the results are shown here (all photomicrographs are taken at 10X). Which one is the most accurate interpretation of these results?

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	Shabnam Zarei, M.D. Fellow, Molecular Genetic Pathology Mayo Clinic
	Kandelaria (Ande) Rumilla, M.D Consultant, Laboratory Genetics and Genomics Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 43-year-old woman presented with a 1.2 cm nodule in the right middle lobe lung. She had a history of triple-negative breast neoplasm diagnosed two years prior for which she underwent a mastectomy. A right middle lobe wedge resection was performed.

Images 1A-1D show lung nodule (H&E)

Images 1E-1I show lung nodule (immunohistochemistry) 

Images 2A-2H show breast mastectomy (H&E)

	Raghavendra Pillappa, M.D. Fellow, Pulmonary Pathology Mayo Clinic
	Anja Roden, M.D. Consultant, Anatomic Pathology Mayo Clinic Associate Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine
	Rafael Jimenez, M.D. Consultant, Anatomic Pathology Mayo Clinic Associate Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 62-year-old female was diagnosed with biopsy-proven metastatic renal cell carcinoma in the head of the pancreas, status/post nephrectomy and ablation. She now presents with two enhancing lesions in the liver (0.5 cm in greatest dimension). Laparoscopic segmentectomy was performed on the two lesions.

	Rebecca Waters, D.O. Resident, Surgical Pathology Mayo Clinic
	Karen Fritchie, M.D. Consultant, Anatomic Pathology Mayo Clinic Associate Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine