Maltese Cross appearance
A term of art referring to a light microscopic appearance of a crystal or crystalloid structure fancifully likened to a Maltese cross, which may correspond to granules of talc, cholesterol or bacteria.
“Maltese crosses” are anisotropic or birefringent cholesterol-rich fat droplets, associated with finely granular renal casts, which have a cruciform appearance by polarised light and are found
both within and outside of the cells in the urine sediment of patients with nephrotic syndrome, eclampsia, renal toxicity, fat embolism, after crush injury and in Fabry’s disease–due to aggregates of glycosphingolipids (the image shows Maltese crosses in urine).
The tetrad form of Babesia spp, most typically seen in B equi, but also in B canis, B
microti, and B bovis, has been termed ‘Maltese cross’ and is a rare but characteristic finding in infected red cells in a peripheral blood smear
Maltese crosses occur in arthroscopic fluid following local trauma and may correspond to cholesterol.
Maltese crosses measure 5-15
mm in diameter, appear as scintillating granules by polarised light microscopy and correspond to starch and talc granules, and are common in the lungs of IV drug abusers who cut (dilute) heroin with powder; the granules may be accompanied by foreign body-type giant cell reaction and appear in other tissues