General overview of small cell lung cancer, small cell lung cancer is the lung (bronchial) epithelium highly malignant, undifferentiated, with neuroendocrine differentiation of cancer. Cancer is small; cytoplasm less ill-defined cells; was slightly granular chromatin, no nucleolus or nucleoli was not significant; fission common.
Small cell lung cancer is highly malignant cancer with neuroendocrine differentiation. Clinical development of rapid, widespread infiltration and metastasis. General overview of small cell lung cancer, the clinical course of less than 3 months. Cough is the most common clinical symptoms of patients, about 75% of patients; followed by chest pain. Small cell lung cancer, the rapid spread of the cancer, surgical resection most patients lose the opportunity; with small cell carcinoma sensitive to chemotherapy, so patients with small cell carcinoma is generally not surgery to remove, the use of chemotherapy and radiotherapy.
(1) general pathological features: small cell lung cancer mainly originated in the large bronchi, such as the lobar bronchus and segmental bronchi. Therefore, small cell lung cancer more than 90% in the hilar region (central type), more than 10% originated in the small bronchi, located in the peripheral lung (peripheral). Cancer grows fast, easy infiltration of the surrounding lung, hilar and mediastinal lymph nodes, forming a huge mass. Often the primary tumor area boundary more clearly, soft; section gray, often accompanied by a large sheet hemorrhage, necrosis, but rarely liquefied necrotic tissue dissolution of cavity formation. Bronchial mucosal lesions can be, so central small cell lung cancer patients, few clinical sputum or hemoptysis hemoptysis in patients with central type of squamous cell carcinoma are different.
(2) histological features: small cell carcinoma of the lung tissue structure is relatively complex, its structure and cell characteristics: diffuse infiltration of cancer tissue, cancer cells arranged in haphazard, mostly in films like Spansion, the middle of delicate fibrous tissue compartment; a small number of cancer cells was afraid of cancer nest-like arrangement and were fence-like structure of pericytes, which is the development of neuroendocrine differentiation like structure; cancer is small, typically round or oval cancer cells form brome ( 0111 ~ 0ll); cytoplasm less densely packed cells, unclear boundaries; clear nuclear outline was quickly fine granular chromatin; no obvious nucleolus or nucleoli; mitotic abnormalities live team.
(3) electron microscopy features: small cell lung cancer, the most important features of the ultrastructure was found in neurosecretory granules within cells: ultra-thin sections in a fixed good, its size does not exceed 200m; particles for the dense central core The most outer limiting membrane integrity in the core and return with a space between. Particles are spherical and relatively uniform shape, but in most cases, clustered in the cytoplasm of the secretory granules that condyle.
(4) Immunohistochemistry: commonly used in small cell lung cancer by immunohistochemistry as follows:
epithelial markers: a. cytokeratin (cytokeratin, CK): hi with a low molecular weight cytokeratins, such as CK8, CK18, CK19, etc., before staining with enzyme digestion, positive 10%, while the use of high molecular weight cytokeratin protein, without the enzyme digestion, the positive rate meter 8%; b. epithelial membrane antigen (EMA): The positive rate of about 50%.
neuroendocrine tests: small cell lung cancer by immunohistochemical methods, can detect more than the book version of the product of prime category, including multiple skin type and glue. Pathological diagnosis often applied in a variety like: a. Neuron specific enolase (neuron-specific enolase, NSE): probability of 50%. However, proof of clinical practice, NSE in neuroendocrine differentiation of the tumor more sensitive to the surface, but not specific; b. neurofilament (neurofilanlent, NF): the main chance of positive expression of 10%; c. wrong tablets hormone (chromogranin, Cg): including CgA and CgB, is inert protein. This marker although not sensitive, but highly specific neuroendocrine differentiation; d synaptophysin (synaptophysin, Svn): are membrane glycoprotein of neurons and neuroendocrine differentiation with high sensitivity and specificity. Positive in small cell lung cancer 20% -80% expression, while in non-small cell lung cancer, the positive rate was 3.8% -8%.
In addition, calcitonin (calcitonin), bell looking skin (bombesin), ACTH, and somatostatin (somatostatin) higher positive rates in small cell lung cancer and other identification have a certain significance.
(5) small cell lung cancer, changes in cell genetics: mainly for the chromosomal variation.
(6) differential diagnosis: small cell lung cancer in the diagnosis, should be addressed to small cell lung tumors.
carcinoid and atypical carcinoid tumors: part of the small cell lung cancer misdiagnosed as atypical carcinoid. Small cell lung carcinoma and carcinoid, atypical carcinoid tumors are the property of pulmonary neuroendocrine tumor, is a common lung cancer. In the differential diagnosis should be noted: a. SCLC is a highly malignant tumor, and carcinoid and atypical carcinoid tumors are low grade and intermediate grade. The former fast tumor progression, and soon spread occurrence, invasion and metastasis; the latter was clinically progressive, slow disease progression; b. carcinoid and atypical carcinoid tumor was a typical organ-like nest-like structure, daisy-shaped tumor cells arranged Mission, ribbon-like, cord-like, tubular-like, more homogeneous tumor cells. The SCLC cell density, deeply stained; c. SCLC different mitotic activity, the average mitotic counts> 801lOHPF, up to 200/10HPF; carcinoid nuclear fission <2/10HPF, atypical carcinoid mitotic 2-lO/lOHPF; d. SCLC more broadly, large necrosis; carcinoid tumors usually no necrosis, atypical carcinoid spotty necrosis; e. neuroendocrine immunohistochemical detection carcinoid, atypical carcinoid positive positive rate is much higher than the SCLC.
small cell lung cancer (SCLC) and pulmonary non-Hodgkin's lymphoma (NHL): a.SCLC with neuroendocrine organ-like nest-like structure, NHL tumor cells is more diffuse, uniform, does not have a specific structure; b.SCLC tumor cell arrangement is more intensive, more diverse forms; NHL tumor cells form a more homogeneous; c.SCLC large sheet was extensive necrosis, vascular wall basophilic, NHL does not have this change; d. rapid development of clinical SCLC, and soon occur far at the transfer; NHL develops slowly, and more distant metastasis; e.SCLC to cytokeratin and neuroendocrine-positive; NHL cell marker antibodies.
small cell squamous cell carcinoma (SSCC): SSCC low differentiation, cancer cells small, granular nuclear chromatin, cell morphology and the SCLC were similar. Identification, attention: a.SSCC cytoplasm of tumor cells showed more obvious nucleoli in total to find the squamous cell carcinoma tissue and cell hierarchy within the keratosis; and lack the characteristics of SCLC neuroendocrine tumors q. cloth organ-like nested structure, rosettes, ribbon-like, cord-like structure, urine, large basophilic necrosis and vascular wall; b. SSCC of epithelial markers generally strongly positive up to 97% -99%; the SCLC low molecular weight CK-positive, EMA positive d of only 50%; c. neuroendocrine labeling antibodies, LC compared with the SSCC, the positive rate was higher expression is also strong; d.SCLC clinical development SCC fast, distant metastasis also earlier; e.SCLC of chemotherapy, radiation sensitive, and SSCCill treatment of choice for the surgery.
(7) small cell lung cancer grade and stage: small cell lung carcinoma is an undifferentiated carcinoma, histopathology, no longer graded.
(8) general overview of small cell lung cancer, small cell lung cancer prognosis: although the tumor to chemotherapy, radiation sensitive, but the survival of about 2
years, so the prognosis is poor.