Pathways Case Studies: Jan. 2019

A 60-year-old man presented with a slow-growing non-painful 4.5 cm mass of the left parotid gland and underwent surgical excision. Below is an hematoxylin and eosin (H&E) section from the periphery of the lesion.

	Kyriakos Chatzopoulos, M.D. Resident, Anatomic and Clinical Pathology Mayo Clinic
	Joaquin Garcia, M.D. Consultant, Anatomic Pathology Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 52-year-old male underwent whole-exome sequencing (WES) for amyotrophic lateral sclerosis (ALS). While no germline alterations relevant to his ALS were detected, multiple de novo mutations associated with hematological malignancy were unexpectedly discovered in ~20% of his sequencing reads, suggesting that these were somatic alterations. Review of the patient’s medical records revealed a persistently low white blood cell count. As a result of these incidental findings, a bone marrow biopsy was performed to assess for possible malignancy.

	Jaime Lopes, Ph.D. Resident, Laboratory Genetics and Genomics Mayo Clinic
	Linda Hasadsri, M.D., Ph.D. Consultant, Lab Genetics/Genomics Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 45-year-old woman presented with a 6 cm nodule in the upper arm. She had removed a bona fide lipoma from the same area >10 years ago. An MRI showed a suspected sarcoma and the lesion was excised.

	Felix Haglund, M.D., Ph.D. Resident, Pathology and Cytology Karolinska University Hospital
	Karen Fritchie, M.D. Consultant, Anatomic Pathology Mayo Clinic Associate Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine