2016年 · 第50卷第04期

Langerhans cell histiocytosis (LCH), formerly known as histiocytosis X, eosinophilic granuloma, Lecher disease, and Hanscher disease, is of unknown cause and is characterized by abnormal proliferation of Langerhans cells (LCs) in one or more organs and tissues, affecting almost any organ, including bone, skin, lung, liver, spleen, bone marrow, and the central nervous system. LCH can occur at any age, usually 1 to 3 years old. The incidence of LCH in children ranged from 0.1 to 1.0 per 100,000^[1]More males than females. Children with LCH are different from adults in the site of onset, clinical manifestations and prognosis. Therefore, an in-depth study of pediatric patients, especially cases with multisystem involvement, is useful for clinical diagnosis, differentiation and treatment. However, unfortunately, there is still a lack of systematic research results in China. Imaging examination is one of the many clinical examinations of LCH. With the continuous improvement of imaging technology and level, it is playing an increasingly important role in the diagnosis, identification, formulation of treatment plan and monitoring of curative effect of this disease.

Male, 22 years old. Four days ago, he developed left ear pain without obvious trigger, intermittent pus discharge, thin pus with xanthaceous color and no odor, and persistent high-profile cicadas in the left ear, accompanied by left eye insufficiency, headache, head confusion and other discomfort. He was admitted to hospital on May 12, 2015. The patient suffered from acute myeloid leukemia 7 years ago and has been cured. MRI showed that a lump shorter T was seen in the left cerebellopontine angle area₁, etc. T₂Signal (Figure 1，Figure 2), edema signal shadows can be seen around it (Figure 2), DWI (b =800 s/mm²) There was no obvious diffusion restriction, and the anterior inner edge of the lesion was closely related to the left auditory nerve trunk; The enhanced scan showed significant uniform enhancement of the mass in the left cerebellopontine angle area, showing "meningeal tail sign" (Figure 3), with the anterior inner margin adjacent to the left auditory trunk. Meningiomas or neurogenic tumors are considered according to MRI. Immunohistochemical staining: cytokeratin (CK), epithelial membrane antigen (EMA), CD123, CD20, CD3 (-), vimentin (Vim), myeloperoxidase (MPO), CD117, D-100 (+), CD163 (partial +), cell antigen proliferation index (Ki-67) 40%. Bone marrow image showed bone marrow granules (+), fat droplets (-), bone marrow hyperplasia was obviously active, granulosis:erythroid =2.52:1, granulosishyperplasia was active (Figure 4), granulocytes can be seen as mesomyelocytes with nucleolus. Combined with morphology, medical history and immunohistochemistry, the diagnosis was left cerebellopontine angle granulocytic sarcoma (GS).

A 46-year-old male was seen in October 2013 with a headache for 1 year and aggravated for 10 d. Laboratory tests are not special. MRI plain scan and enhanced examination of the head showed: the space-occupying lesions in the supratentorial and inferior tentorial of the right cerebellum, about 2.9 cm ×2.3 cm ×3.3 cm in size, irregular in shape, locally lobulated, T₁WI is heterogeneous etc. -slightly lower signal (Figure 1）； T₂WI showed high-low confounding signals, with annular hyposignal shadows, moderate perifocal edema, compressive deformation of the fourth ventricle, and migration of the pons (Figure 2）。 The lesions were obviously unevenly enhanced on enhanced scan, and the non-enhanced areas in the lesions suggested necrosis; The lesion grew across the tentorium, with adjacent meningeal line-like enhancement (Figure 3）。 MRI diagnosis is that it originates from meningeal tumor, and the malignancy may be large.

A 65-year-old male was seen on April 9, 2015 due to sudden and persistent retrosternal pain for 3 h. Admission examination: blood pressure 103/60 mmHg (1 mmHg =0.133 kPa), normal development, moderate nutrition, acute painful facial appearance, no cyanosis of the lips, no bulge in the precordial area, heart rate 60 beats/min, arrhythmia, strong heart sounds, no murmur in each valve area of the heart, and no tremor in the precordial area. Electrocardiogram showed: sinus arrhythmia, ST segment elevation 0.1 mV in lead Ⅱ, Ⅲ and avF, and ST segment elevation 0.1 mV in lead V, considering acute myocardial infarction (inferior wall, posterior wall). Color ultrasound examination of the heart showed no abnormalities in the intracardiac structure. Laboratory tests: Arterial blood gas analysis showed an oxygen partial pressure of 53 mmHg and an oxygen saturation of 88%. CT pulmonary artery imaging (CTPA) was performed to exclude pulmonary embolism. On April 15, 2015, the coronary angiography examination showed that there was no abnormality in the left main trunk, mild stenosis in the proximal segment of the left anterior descending artery, diffuse severe stenosis in the middle segment of the left circumflex artery, local nearly occlusion, the degree of stenosis was 99%, and diffuse stenosis in the distal segment of the right coronary artery, with a maximum stenosis of 90%.

Female, 11 years old. Lower back kyphosis was found and admitted 10 d. The patient had no trauma, fever, and no history of primary tumor and tuberculosis. Past physical fitness. Physical examination: kyphosis deformity, no redness, swelling and damage on the surface skin. Laboratory test: white blood cells 7.78×10⁹/L, the percentage of eosinophils was 4.90%, all within the normal range.

Female, 29 years old. Abdominal pain, diarrhea and anorexia lasted for more than 2 months, but there was no significant relief after nutritional support treatment. The patient's mental state and appetite were poor since the onset of the disease. Laboratory test: Hemoglobin 87×10⁹g/L (normal reference value: 115×10⁹~150×10⁹g/L), leukocytes 35.2×10⁹g/L (normal reference value: 3.5×10⁹~9.5×10⁹g/L), C-reactive protein 82.5 mg/L (normal reference value: 0-5 mg/L), erythrocyte sedimentation rate 51 mm/1 h (normal reference value: 0-20 mm/1 h), anti-gliadin antibody positive. CT examination: The distal duodenum and proximal jejunum walls were obviously thickened, the intestinal wall was slightly dilated, and multiple small fluid levels were seen, and multiple enlarged lymph nodes were seen in the retroperitoneum and mesentery (Figure 1）。 MRI examination: the jejunal lumen is slightly narrow, the mucosal folds are widely atrophic, sparse and disordered, the local intestinal wall of jejunum and ileum is edema and thickened, the ileal lumen is widened, and there are multiple small lymph nodes in the retroperitoneum (Figure 2，Figure 3）。 The local intestinal wall thickening of the ileum showed obvious enhancement in the early stage and was mainly on the mesenteric side, with local thickening of mesenteric blood vessels (Figure 4）。 Gastrointestinal endoscopy biopsy, pathology showed severe chronic active inflammation of the descending duodenum, bulb, and terminal ileum mucosa, significant atrophy of villi, and more lymphocyte infiltration in epithelial cells, which was consistent with gelatin enteropathy (celiac disease).

Male, 60. The right upper abdomen is distended and distended for more than 2 months. He had a history of chronic hepatitis B virus, and had a solid space-occupying lesion in the liver after abdominal ultrasound examination in an external hospital. Laboratory tests: Alanine aminotransferase, aspartate aminotransferase, direct bilirubin were slightly elevated, and tumor markers were normal.

Female, 49 years old. Due to intermittent abdominal pain and melena for more than 1 year, it was admitted to hospital for 8 days. Physical examination: anemia, soft abdomen, tenderness in the right upper abdomen, no rebound pain and muscle tension. Laboratory test: red blood cells 2.7×10¹²/L (normal reference value: 3.5×10¹²~5.0×10¹²/L), hemoglobin 76 g/L (normal reference value 110~150 g/L), and there were no abnormalities in digestive tract tumor markers. One month before admission, abdominal CT scan revealed a soft tissue mass in the proximal jejunum with uneven internal density and structural disorder in the descending and horizontal segments of the duodenum (Figure 1）。 After admission, abdominal enhanced CT showed inhomogeneous enhanced high-density shadows in the junction between the descending and horizontal segments of the duodenum, with some unclear boundaries, and the size was 2.5 cm ×2.4 cm (Figure 2）； No lesions were found in the proximal jejunal cavity, and the diagnosis was a descending duodenal mass with duodenojejunal intussusception. Because the patient's symptoms persisted, the gastroscopy and abdominal enhanced CT were re-examined 3 days later. The gastroscopy showed a huge tumor in the descending duodenum, with a size of 7.0 cm ×3.0 cm, with a thick pedicle, and its base was located at the entrance of the descending part. The head of the tumor was rough and easy to bleed when touched, and the surface of the tumor near the base was smooth (Figure 3）； Enhanced CT scan showed a slightly enhanced mass-like soft tissue density shadow in the proximal jejunum, and the descending and horizontal segments of the duodenum were inserted into the distal small intestine, with a local 4-layer intestinal wall structure, and multiple cystic low-density shadows were seen on the head side of the tumor (Figure 4）。 Combined with the results of multiple CT and gastroscopy, the diagnosis was descending duodenal tumor with recurrent intussusception.

Langerhans cell histiocytosis (LCH) is a proliferative disease of abnormal histiocytes (Langerhans cells) in local or systemic tissues, which can cause local and extensive organ or tissue damage. LCH was originally named as three separate diseases: Letterer-Siwe disease, Hand-Schuller-Christian disease, and eosinophilic granuloma, which are actually manifestations of different types or different stages of development of the same disease. In 1953, Lichtenstein collectively referred to these three diseases as histiocytosis X (HX), and in 1987, the International Histiocyte Association renamed them Langerhans cell histiocytosis (LCH).