Marginal Zone Lymphoma
Lessons From the Friday Unknowns Histologic sections show fragments of fibroadipose tissue involved by an atypical lymphoid infiltrate focally arranged in nodules and sometimes separated by fibrous septa. The lymphoid cells are small, with mature chromatin and scant to moderate amounts of cytoplasm. Occasional large cells are seen, no apoptotic bodies and no necrosis present.
B-Cell Lymphoma with a Folliuclar Immunophenotype Involving the Skin: Primary Cutaneous Follicle Center Lymphoma vs Large Follicular Lymphoma
Lessons From the Friday Unknowns Histologic sections show fragments of skin and deep dermis involved by lymphoma. The lymphoma has a follicular pattern and is composed predominantly of cleaved and non-cleaved centroblasts, with scattered small centrocytes in the background. No epidermotropism seen.
Nodal T-Follicular Helper Cell Lymphoma, Angioimmunoblastic-Type
Lessons From the Friday Unknowns Sections show lymph nodes with complete effacement of the architecture, by a diffuse infiltrate of intermediate size lymphocytes, plasma cells and histiocytes. There is increased vasculature. The neoplastic cells are small to intermediate in size with clear to pale cytoplasm. The nuclei display irregular contours with mature chromatin. There are…
Primary Cutaneous Anaplastic Large Cell Lymphoma with IRF4/DUSP22 Rearrangement
Lessons From the Friday Unknowns The skin biopsy shows a dense dermal infiltration with epidermotropism. The infiltrating lymphocytes ranging in size from small to medium size. The epidermis shows epidermotropism of smaller lymphocytes, few of which few are cerebriform. The neoplastic cells display irregular nuclear contours with occasional prominent nucleoli. The cytoplasm is scant to…