Small yellow tumor-like rash

Introduction Small yellow tumor rash is common in acute neuronal Niemann's disease, also known as sphingomyelinosis, a congenital glycolipid metabolic disease. It is characterized by a large number of foam cells containing sphingomyelin in whole mononuclear macrophages and the nervous system. The sphingomyelin is formed by linking N-acetyl sphingosine to a molecule of phosphorylcholine at the C1 site. The sphingomyelin is derived from various cell membranes, red blood cell matrices and the like. It is engulfed by macrophages during cellular metabolic senescence.

Cause

The disease is a sphingomyelinase deficiency-induced sphingomyelin metabolism disorder. The latter accumulates in the mononuclear 0 macrophage system, with liver and splenomegaly, and degeneration of the central nervous system.

The activity of this enzyme is highest in normal liver, and the liver, kidney and brain small intestine are also rich in this enzyme. The activity of the enzyme in the liver, spleen and other tissues of the patient is reduced to less than 50%. In the whole body reticuloendothelial system, large foam cells with a diameter of 20-90 m rich in lipids can be found, mainly in the spleen, bone marrow, liver, lung and lymph nodes. This kind of foam cell is also called Niemann-Pick cell, usually only a small cell nucleus with a biased position, loose chromatin; cytoplasm filled with lipid droplets (cytoplast), "mulberry" on unstained tablets, Giemsa When dyeing, the cytoplasm is blue or blue-green with blue particles of different shades. Unlike Gaucher cells: acid phosphatase staining is weakly positive. The Schultz reaction (detection of cholesterol) was positive. Both can be identified by phase microscopy or electron microscopy.

In 1194, 1 patient was reported and the patient died at 18 months of age. It was discovered in 1934 that it is a neurophosphorus sedimentary disease. It was only discovered in 1966 that it was caused by a lack of neurophospholipidase. After the enzyme is absent, the systemic sphingomyelin metabolism is disordered, and the neurolipids are deposited in the mononuclear-macrophage system and nerve tissue cells.

an examination

Related inspection

Trace element detection in human body

1. Hemoglobin is normal or has mild anemia; leukocytes decrease when spleen is present. Monocytes and lymphocytes often display characteristic vacuoles, about 8 to 10, and have diagnostic value. These vacuoles are filled with lipid lysosomes under electron microscopy. The number of platelets was normal, and the time to spleen and bone marrow was significantly reduced in the late stage. Patients with leukocytes lack neurophospholipidase activity.

2, bone marrow contains a typical slow-pick cells, often called foam cells, nuclear cells diameter 20 ~ 100m. The nucleus is small, round or oval, usually single or dual-core. The cytoplasm is rich, filled with round droplets of transparent vesicles, similar to mulberry-like or foamy. Electron microscopy showed that some of the membrane structure surrounds the vesicles. Examination of unstained specimens by phase microscopy revealed a small bubble in the cytoplasm, which is different from high snow cells. The vesicles were birefringent when observed under polarized light. The fluorescence is green and yellow under ultraviolet light. The biochemical characteristics of PAS were weakly positive, the vesicle wall was positive in the cytoplasm, and the vesicle center was negative; acid phosphatase, alkaline phosphatase and Sudan black were negative.

3, plasma cholesterol, total lipids can be elevated, SGPT mildly elevated.

4, urinary excretion of sphingomyelin increased significantly.

5, liver, spleen and lymph node biopsy have piles, pieces or diffuse foam cell infiltration. Sphingomyelin.

6, X-ray examination: no characteristic X-ray performance, in long-term survival cases, due to the proliferation of fat-filled tissue cells in the bone can be expressed osteoporosis, medullary cavity widening, cortical thinning, and even long bones can appear focal Sexually disrupted areas, but no bone swelling and deformity changes. After infancy, the alveoli are infiltrated by fat-filled tissue cells, and the lungs are similar to those of histiocytosis. In summary, there is no specificity and only the basis for assisted diagnosis is provided.

7. Determination of sphingomyelinase activity of leukocytes or cultured fibroblasts, and different types of enzyme activities.

Differential diagnosis

Sweat tube tumor is also known as sweat tube cystic tumor or sweat tube cyst adenoma. This disease occurs in women, puberty. Multiple lesions are seen on the face, especially the eyelids, neck and chest. A small number of patients have rash, except for the face, the chest, abdomen and limbs can have a wide range of symmetry rash. The rash is a skin-colored, pale yellow or brown flat papule with a diameter of 1 to 3 mm. It is solid, can be clustered but not fused, and generally has no symptoms. Some patients have itching or burning sensation due to difficulty in sweating in summer.

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