​A 46-year-old woman presented for surgical management of endometriosis and underwent a total hysterectomy and bilateral salpingo-oophorectomy. In addition to typical-appearing leiomyomata, a well-circumscribed, soft, yellow tumor was identified.

Amy A. Swanson, M.D.
Resident, Anatomic Pathology/Neuropathology
Mayo Clinic

J. Kenneth Schoolmeester, M.D.
Consultant, Division of Anatomic Pathology
Mayo Clinic
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine

This case study reviews a ​24-year-old man with a large solitary liver mass.

	Nooshin Karamzadeh Dashti, M.D. Fellow, Surgical Pathology Mayo Clinic
	Rondell Graham, M.B.B.S. Senior Associate Consultant, Anatomic Pathology Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 70-year-old female presented with peripheral blood lymphocytosis and hepatosplenomegaly. Below are the peripheral blood and bone marrow aspirate findings:

Karyotype cytogenetics revealed inv(14)(q11q32), with the rearrangement involving the TCL1 oncogene (confirmed by FISH).

	Basma Basha, M.D. Fellow, Hematopathology Mayo Clinic
	Rebecca L. King, M.D. Consultant, Division of Hematopathology Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine

A 49-year-old HIV-positive gentleman presents to his local medical center with cervical lymphadenopathy without a known associated pleural effusion. A needle core biopsy is performed. Within the perinodal soft tissue (top of Figure 1A), there is an atypical infiltrate of large pleomorphic cells (Figure 1). These cells do not express cytokeratin (Cam 5.2 or OSCAR), SOX10, CD3, CD20, CD30, CD45, or CD79a. These cells do express CD43, CD138, and MUM1 (Figure 2). Both in situ hybridization studies for Epstein-Barr virus (EBV) and an immunohistochemical stain for human herpes virus 8 (HHV-8) are positive (Figure 3).

Justin Juskewitch, M.D., Ph.D. Resident, Anatomic/Clinical Pathology Mayo Clinic

Karen Rech, M.D. Consultant, Division of Hematopathology Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine