Comprehensive analysis of gene mutations and mismatch repair in Chinese colorectal cancer patients

BACKGROUND RAS,BRAF,and mismatch repair(MMR)/microsatellite instability(MSI)are crucial biomarkers recommended by clinical practice guidelines for colorectal cancer(CRC).However,their characteristics and influencing factors in Chinese patients have not been thoroughly described.AIM To analyze the clinicopathological features of KRAS,NRAS,BRAF,and PIK3CA mutations and the DNA MMR status in CRC.METHODS We enrolled 2271 Chinese CRC patients at the China-Japan Friendship Hospital.MMR proteins were tested using immunohistochemical analysis,and the KRAS/NRAS/BRAF/PIK3CA mutations were determined using quantitative polymerase chain reaction.Microsatellite status was determined using an MSI detection kit.Statistical analyses were conducted using SPSS software and logistic regression.RESULTS The KRAS,NRAS,BRAF,and PIK3CA mutations were detected in 44.6%,3.4%,3.7%,and 3.9% of CRC patients,respectively.KRAS mutations were more likely to occur in patients with moderate-to-high differentiation.BRAF mutations were more likely to occur in patients with right-sided CRC,poorly differentiated,or no perineural invasion.Deficient MMR(dMMR)was detected in 7.9% of all patients and 16.8% of those with mucinous adenocarcinomas.KRAS,NRAS,BRAF,and PIK3CA mutations were detected in 29.6%,1.1%,8.1%,and 22.3% of patients with dMMR,respectively.The dMMR was more likely to occur in patients with a family history of CRC,aged<50 years,right-sided CRC,poorly differentiated histology,no perineural invasion,and with carcinoma in situ,stage I,or stage II tumors.CONCLUSION This study analyzed the molecular profiles of KRAS,NRAS,BRAF,PIK3CA,and MMR/MSI in CRC,identifying key influencing factors,with implications for clinical management of CRC.

Micronodular thymic tumor with lymphoid stroma: A case report and review of the literature

BACKGROUND Micronodular thymic tumors with lymphoid stroma include micronodular thymoma with lymphoid stroma(MNT)and micronodular thymic carcinoma with lymphoid hyperplasia(MNC),whose micromorphological features are lymphoid stromal hyperplasia and nodular arrangement of tumor epithelial cells.This type of tumor is rare;therefore,the corresponding clinical guidelines,histopathological diagnostic criteria,prognostic factors,and therapeutic regimens have not been established.CASE SUMMARY This study covers a novel presentation of MNC in a patient and summarizes the clinicopathological characteristics of this type of tumor by using pooled-analysis methods.Morphologically,this tumor type is a series of benign to malignant pedigrees.We establish the following criteria for the classification of micronodular thymic tumors with lymphoid stroma:(1)Tumor cells with moderate-to-severe dysplasia;(2)Tumor cell mitotic figures>2/10 high-power fields;(3)Appearance of neoplastic necrosis;(4)No terminal deoxynucleotidyl transferase-positive immature T lymphocytes within the tumor;(5)Tumor cells with a Ki-67 index≥10%;and(6)Tumor cells express CD5.Cases that fall into the borders of two categories in terms of morphology are attributed to atypical MNT.It is proposed that the diagnosis of MNT should be established on the diagnostic criteria mentioned above.CONCLUSION Our diagnostic algorithm can effectively distinguish malignant tumors from benign tumors and provides a potent basis for predicting a prognosis,which offers a practical reference for oncologists and pathologists.

Comparison of Clinical and Ultrasonographic Features of Poorly Differentiated Thyroid Carcinoma and Papillary Thyroid Carcinoma

Background： The clinical behavior and management of poorly differentiated thyroid carcinoma （PDTC） are very different from papillary thyroid carcinoma （PTC）. By comparing the clinical and ultrasonographic features between the two tumors, we proposed to provide more possibilities for recognizing PDTC before treatment. Methods： The data of 13 PDTCs and 39 ageand gender-matched PTCs in Peking Union Medical College Hospital between December 2003 and September 2013 were retrospectively reviewed. The clinical and ultrasonic features between the two groups were compared. Results： The frequencies of family history of carcinoma, complication with other thyroid lesions, lymph node metastases, recurrent laryngeal nerve injuries, and distant metastases were higher in PDTCs （30.8%, 61.6%, 69.2%, 23.1%, and 46.2%, respectively） than those in PTCs （2.6%, 23.1%, 25.6%, 2.6%, and 2.6%, respectively） （P 〈 0.05）. The mortality rate of PDTCs was greatly higher than PTCs （P 〈 0.01）. Conventional ultrasound showed that the size of PDTCs was larger than that of PTCs （3.1±1.9 cm vs. 1.7± 1.0 cm）. Clear margins and rich and/or irregular blood flow were found in 92.3% of PDTCs, which differed substantially from PTCs （51.7% and 53.8%, respectively） （P 〈 0.05）. Conclusions： PDTC is more aggressive and its mortality rate is higher than PTCs. Accordingly, more attention should be given to suspicious thyroid cancer nodules that show large size, regular shape, and rich blood flow signals on ultrasound to exclude the possibility of PDTCs.

Anti-Ma2 Paraneoplastic Encephalitis Associated with Ileal Lymphoma

To the Editor： Ma2 antibody-mediated encephalitis is a rare type of paraneoplastic neurological syndrome （PNS） present with various clinical symptoms. Lung or testicular germ-cell malignancies are the most commonly associated tunlors,lH Here, we reported a patient with a Ma2 antibody-mediated encephalitis related to ileal lymphoma.

Clinically applicable Gleason grading(GD)system for prostate cancer based on deep learning

To the Editor:Prostate cancer is one of the most common malignant tumors of the male genital system,with approximately 1.1 million new cases in 2012.[1]The accurate diagnosis of prostate cancer leads to a better chance of successful treatment when it is still confined to the prostate gland.The Gleason grading(GD)system was first established by Donald Gleason during 1966 to 1974.[2,3]The Gleason pattern ranges from 1 to 5.A higher score corresponds to poorer differentiation,which indicates a worse prognosis and higher metastasis possibility.The total score is calculated with the first half of the dominant Gleason pattern and the second half based on the non-dominant one.

A case report on subarachnoid and intraventricular neurocysticercosis

Neurocysticercosis is the most common central nervous system helminthic infection in humans.We hereby present a case combining two rare manifestations of neurocysticercosis:the subarachnoid and intraventricular forms.The patient presented with hydrocephalus and neurologic deficits and although endoscopic removal of the cysts and two cycles of postoperative cysticidal drugs resulted in resolution of symptoms,they later recurred.Ventriculoperitoneal shunt placement and a further cycle of albendazole plus dexamethasone led to substantial clinical improvement.Extraparenchymal neurocysticercosis may be challenging to diagnose and treat and is usually associated with a poorer prognosis.Clinicians should be aware of this condition.

Xanthogranuloma of the Sellar Region

To the Editor： A 36-year-old female patient was admitted to Peking Union Medical College Hospital complaining of 6 years of headache. Magnetic resonance imaging （MRI） showed an intrasellar lesion with homogeneous hyperintense on T 1-weighted images and T2-weighted images and inhomogeneous contrast enhancement by the gadolinium administration [Figure l a and lb]. Rathke＇s cleft cyst was initially diagnosed preoperatively, and the tumor was totally resected by transsphenoidal surgery. Histopathology revealed that granulomatous tissue consisted of cholesterol clefts, lymphoplasmacellular infiltrates, marked hemosiderin deposits, and multinucleated foreign body giant cells around cholesterol clefts [Figure 1 e- 1 g].