Pathways Case Studies: January 2020

A 27-year-old man underwent amputation of the right fourth toe for a soft tissue mass.

	Kyriakos Chatzopoulos, M.D. Resident, Anatomic and Clinical Pathology Mayo Clinic
	Andrew Folpe, M.D. Consultant, Anatomic Pathology Mayo Clinic Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine and Science

Chimeric antigen receptor T cells (CAR T cells) represent an exciting new area of cellular therapy. Manufacturing autologous CAR T cells involves virally transducing a patient’s T cells to express a receptor to heighten recognition of tumor-specific antigens. From a regulatory standpoint, CAR T cells are subject to regulation both as a drug and as a biological product. This presents ongoing challenges for cellular therapy programs and laboratories that seek to develop in-house manufacturing of next-generation CAR T cell products.

	Ashley Krull, Ph.D. Fellow, Cellular Therapy Mayo Clinic @AshleyAKrull
	Allan Dietz, Ph.D. Consultant, Transfusion Medicine Mayo Clinic Associate Professor of Laboratory Medicine and Pathology Instructor in Biochemistry and Molecular Biology Mayo Clinic College of Medicine and Science

A 19 year old female with a complex phenotype suggestive of a mitochondrial disorder had mitochondrial DNA sequencing performed three times at an outside institution, all with inconclusive results due to “multiple heteroplasmic positions”. Mitochondrial genome sequencing was performed here revealing 6 benign homoplasmic and 21 benign variants at 10-20% heteroplasmy. When variants are stratified by frequency, this patient appears to have two distinct haplogroups (Figs A-B). Normally individuals have only one haplogroup, which is maternally inherited.

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

This is a surgical pathology case of a 70-year-old woman with multiple bilateral relatively stable lung nodules and history of metastatic leiomyosarcoma of Mullerian origin status post debulking 4 years ago. During frozen section the rectosigmoid resection and the liver biopsy showed involvement by leimyosarcoma. However, the lesion found on a lung wedge resection could only be described as a biphasic tumor. On permanet section this lesion’s findings are shown below.

	Simone Barreto Siqueira Parrilha Terra, M.D. Resident, Cytopathology Mayo Clinic
	Joanne (Eunhee) Yi, M.D. Consultant, Anatomic Pathology Mayo Clinic Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine and Science