There are a few terms in pathology that should automatically make you think of specific diseases. In hematopathology, “cerebriform lymphocyte” should make you think of Sezary syndrome/mycosis fungoides; “hypersegmented neutrophil” should bring to mind megaloblastic anemia, and the crude but descriptive “butt cell” should summon up follicular lymphoma (when follicular lymphoma cells circulate in the blood, they often have a derriere-like appearance due to large clefts that extend deeply into the cell).

Another such term is “starry-sky pattern.” In Burkitt lymphoma (which is, by the way, the same thing as B-cell acute lymphoblastic leukemia), the histologic sections have a unique appearance at low power, as seen in the above image. The tumor cells, which are large with minimal cytoplasm, are closely apposed to each other, forming a dark blue background (the “sky”). These cells have a very high turnover rate, so the macrophages that happen to be hanging around get stuffed with cellular debris (they are at this point called “tingible body macrophages”), and upon fixation, the cytoplasm falls away, leaving round white spaces filled with debris (the “stars”). This pattern can be seen on both bone marrow or lymph node sections, and it is quite specific for Burkitt lymphoma.

By the way, tingible body macrophages in and of themselves are not malignant, and they are seen in conditions other than Burkitt lymphoma. In normal germinal centers, for example, they are abundant. This is a point where students often say, well how am supposed to tell, then, whether it is Burkitt lymphoma or a benign reactive lymphadenopathy with germinal centers? The answer is: you have to look at the cells surrounding the tingible body macrophages. If there are sheets of medium-sized dark blue cells, with a high mitotic rate and no architectural pattern whatsoever, it’s probably Burkitt lymphoma. If there are follicles with a mantle zone (dark blue) surrounding a central germinal center (which, by the way, is composed of a ton of different kinds of cells – little ones, big ones, cleaved ones, non-cleaved ones), it’s probably a benign reactive process.