Which histological feature is characterized by sheets of medium-sized lymphoid cells with a "starry sky" appearance?

The histological feature characterized by sheets of medium-sized lymphoid cells with a "starry sky" appearance is most specifically associated with Burkitt's lymphoma. This distinctive appearance is a result of a high proliferation of lymphocytes interspersed with macrophages that have phagocytized apoptotic cells and cellular debris, giving the visual impression reminiscent of a starry sky.

In Burkitt's lymphoma, the "starry sky" pattern arises from the aggressive proliferation of B-cells due to the MYC gene rearrangement, often linked to chromosomal translocations involving chromosome 8. The presence of tangible body macrophages contributes significantly to this histological appearance, as they clear away necrotic debris, enhancing the contrast of the lymphoid cells.

This striking microscopic finding aids pathologists in diagnosing Burkitt's lymphoma, particularly within the context of its clinical presentation, which may also involve rapid progression and association with certain infections, such as Epstein-Barr virus. Understanding the unique histological characteristics of different lymphomas is crucial for accurate diagnosis and appropriate management.