Niemann-Pickrsquo;s disease (NPD) is an inherited metabolic disease caused by the deposition of sphingomyelin and cholesterol in various organs of the body. The disease was first reported by Niemann in 1914 as the first case, and in 1922 Pick described in detail what was seen on pathological examination, hence the name. Two cases were first reported in China in 1963, and individual cases have been reported since then. What are the examination methods for Niemann-Pick disease? 1.Blood picture examination There may be moderate anemia and thrombocytopenia, the degree of which depends on the extent of bone marrow involvement. Leukocytes are generally normal, may be reduced or even slightly increased, and lymphocytes and monocytes may have vacuoles. Bone marrow examination The degree of bone marrow hyperplasia and the ratio of various cells are normal. Typical Niemann-Pick cells can be found, which are 20-90μm in diameter, round, oval or triangular, containing an eccentric smaller nucleus, and the cytoplasm is filled with foamy neurospinal myelin particles resembling mulberry-like fat droplets. The Ritter stain is light blue, lipid (Sudan III) stain is positive, glycogen stain is positive for the vacuolar wall and negative for the vacuolar center, alkaline phosphatase and peroxidase stain is negative. 3.X-ray examination There may be corn-like infiltration in the lungs, mild enlargement of the medullary cavity and thinning of the bone cortex in type A, gray matter degeneration, demyelinating lesions and cerebellar atrophy in brain CT and MRI examination. 4, enzyme assay Leukocytes, skin biopsy fibroblast culture to determine sphingomyelinase are reduced. 5, kidney biopsy Light microscopy of renal tubular epithelial cells, glomerular wall layer, dirty layer epithelial cells are foamy degeneration. Under electron microscopy, some renal tubular epithelial cells showed zebra vesicles, while others showed atypical concentric circle arrangement. 6.Other examinations Skin fibroblast culture detects cholesterol esterification, which is impaired in type C. Simultaneous philippin staining shows accumulation of unesterified cholesterol in lysosomes. Rectal biopsy can clearly show deposition in type C neuronal cells before the onset of neurological symptoms (sometimes several years).