Histologic sections from a rapidly enlarged cervical lymph node in a 35-year-old female reveal a diffuse, monotonous proliferation of small, noncleaved lymphocytes, which are forming a "starry sky" appearance because numerous tingible-body macrophages are present. A touch prep reveals that many of these cells have cytoplasmic vacuoles, which would most likely react with

Burkitt's lymphoma, or undifferentiated lymphoma, is characterized by a rapid proliferation of primitive lymphoid cells with thick nuclear membranes, multiple nucleoli, and intensely basophilic cytoplasm when stained with Wright's stain. The cells are often mixed with macrophages in biopsy, giving a starry sky appearance. The cytoplasmic vacuoles of the lymphoma cells contain lipid, and this would be reflected by a positive oil red O reaction. PAS stain is nonspecific but does mark neutrophils and acute lymphoblastic leukemia cells. Nonspecific esterase is found predominantly within monocytes but also in megakaryocytes. Chloracetate esterase and myeloperoxidase are primarily found within the lysosomes of granulocytes, including neutrophils, promyelocytes, and faintly in rare monocytes Reference: Robbins & Cotran Pathologic Basis of Disease, 9edition.