A 32-year-old male presents to clinic for irritation of his back for about a year and a half. He has noticed episodic asymptomatic rashes mostly on his right back. He was prescribed triamcinolone and a sensitive skin care regimen by his primary care physician with minimal improvement. He also reported the development of a new lesion on the right upper back that fluctuates in size and is occasionally tender but does not drain. He denies fevers, chills, or unintentional weight loss. Two skin biopsies were performed and immunohistochemistry shows B cells that label with CD20, CD21, and BCL2, negative for CD10 (Figure 1) as well as plasma cells that label with kappa (Figure 2).
Based on the patient history and pathology, what is the most likely diagnosis?
A.) Mycosis Fungoides
B.) Primary cutaneous marginal zone lymphoma
C.) Primary cutaneous follicle center lymphoma
D.) Primary cutaneous large B cell lymphoma, leg type
E.) Lymphocytoma cutis