Atypical thymic carcinoid tumor with ectopic ACTH syndrome in a 33-year-old male patient: A rare case report and literature review.

RATIONALE: Atypical thymic carcinoid tumor is an exceedingly rare thymic neuroendocrine tumor derived from the cells of neuroendocrine system. Misdiagnosis or delayed diagnosis may result in disease progression to advanced stages and eventually leads to a poor prognosis. It is therefore necessary to make a correct diagnosis and provide an adequate treatment. PATIENT CONCERNS: A 33-year-old Chinese male presented with numbness in bilateral lower extremities and general fatigue for a month. Chest computed tomography revealed a superior anterior mediastinal mass. Thymoma was initially considered, given the location of the mass and radiographic presentation. DIAGNOSIS: Microscopic findings showed that the tumor cells are arranged in pseudoepitheliomatous growth or irregular nested growth pattern in a background of fibroconnective tissue, with focal infiltration into adipose tissue. The chrysanthemum-like structure or beam-like structure seen often in typical carcinoid tumor was not identified in this case. The tumor cells are spindled or oval, with focal active mitosis. The immunohistochemical staining showed strong positivity for CD56, CgA and Syn, positivity for CK, ACTH, and TTF-1, negativity for Vimentin, and ki67 labeled proliferation index was up to 10% in focal areas. According to the radiological and pathological findings, the diagnosis of atypical thymic carcinoid was made. INTERVENTIONS: The patient underwent surgical resection of the mass. OUTCOME: No recurrence or metastasis was identified during the follow up. LESSONS: Because of its low incidencen, onspecific clinical symptoms, tissue location, and radiological findings, atypical thymic carcinoid tumor may sometimes be misdiagnosed as thymoma. Attention should be paid to avoid misdiagnosis.

Endometrioid adenofibroma of ovary: A case report and review of literature.

RATIONALE: Endometrioid adenofibroma is a benign epithelial neoplasm of the ovary, most of which are often unilateral. The symptoms of endometrioid adenofibroma are often nonspecific and misleading. Therefore, a full understanding of the characteristics, diagnosis, and treatment methods of this disease is of great importance. In this study, we report a 34-year-old woman who was found with an unidentified mass on the right ovary during the physical examination 3 years ago with nosymptoms or signs. PATIENT CONCERNS: A 34-year-old Chinese female was found with an unidentified 6 cm mass on the right ovary for 3 years that presented with no symptoms or signs. DIAGNOSIS: Pelvic ultrasound revealed a 6 cm cystic solid mixed mass on the right ovary. Through histological and immunohistochemical examinations, the tumor mass was finally diagnosed as endometrioid adenofibroma of ovary. INTERVENTIONS: To confirm the diagnosis, the ovarian tumor was laparoscopically resected. OUTCOMES: The patient returned to hospital after 3 months with no recurrence or postoperative complications. LESSONS: Endometrioid adenofibroma is a benign epithelial neoplasm of the ovary. Complete surgical resection is required and rare cases can recur. Postsurgical pathologic and immunohistochemical testing can confirm a diagnosis of endometrioid adenofibroma. It is important to understand of the key points of differential diagnosis of the disease due to the different prognosis and clinical treatment.

A single protective polymorphism in the prion protein blocks cross-species prion replication in cultured cells.

The bank vole (BV) prion protein (PrP) can function as a universal acceptor of prions. However, the molecular details of BVPrP's promiscuity for replicating a diverse range of prion strains remain obscure. To develop a cultured cell paradigm capable of interrogating the unique properties of BVPrP, we generated monoclonal lines of CAD5 cells lacking endogenous PrP but stably expressing either hamster (Ha), mouse (Mo), or BVPrP (M109 or I109 polymorphic variants) and then challenged them with various strains of mouse or hamster prions. Cells expressing BVPrP were susceptible to both mouse and hamster prions, whereas cells expressing MoPrP or HaPrP could only be infected with species-matched prions. Propagation of mouse and hamster prions in cells expressing BVPrP resulted in strain adaptation in several instances, as evidenced by alterations in conformational stability, glycosylation, susceptibility to anti-prion small molecules, and the inability of BVPrP-adapted mouse prion strains to infect cells expressing MoPrP. Interestingly, cells expressing BVPrP containing the G127V prion gene variant, identified in individuals resistant to kuru, were unable to become infected with prions. Moreover, the G127V polymorphic variant impeded the spontaneous aggregation of recombinant BVPrP. These results demonstrate that BVPrP can facilitate cross-species prion replication in cultured cells and that a single amino acid change can override the prion-permissive nature of BVPrP. This cellular paradigm will be useful for dissecting the molecular features of BVPrP that allow it to function as a universal prion acceptor.

Intra-tumoral angiogenesis correlates with immune features and prognosis in glioma.

Gliomas are the most common malignant tumor in the brain. As with other tumors, the progression of glioma depends on intra-tumoral angiogenesis. However, the effect of angiogenesis on gliomas is still not fully understood. In this study, we developed an angiogenesis pathway score using Gene Set Variation Analysis (GSAV) in R to assess the status of intra-glioma angiogenesis in The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA mRNAseq_325, CGGA mRNA-array), and GSE16011 datasets. We found that the angiogenesis pathway score not only accurately predicted the prognosis of glioma patients, but also accurately distinguished the malignant phenotype and immune characteristics of gliomas. In addition, as an independent prognostic factor, the score could predict glioma sensitivity to radiotherapy and chemotherapy. In summary, we used the angiogenesis pathway score to reveal the relationship between glioma angiogenesis and the malignant phenotype, immune characteristics, and prognosis of glioma.

Pulmonary artery intimal sarcoma mimicking pulmonary thromboembolism: A case report.

RATIONALE: Pulmonary artery intimal sarcoma is a rare tumor with exceptionally high mortality and easily misdiagnosed as pulmonary thromboembolism pulmonary thromboembolism (PTE) due to the nonspecific clinical presentation and symptom. Misdiagnosis or untimely diagnosis makes the disease progress to an advanced stage and eventually leads to a poor prognosis. PATIENT CONCERNS: A 37-year-old Chinese female presented with chest tightness and dyspnea for 3 months. Echocardiography and chest computed tomography revealed an intraluminal obstruction of the pulmonary arteries. Tests of serum tumor makers showed slight elevation for carbohydrate antigen-125, and α-fetoprotein. PTE was suspected according to the radiological and laboratory findings. DIAGNOSIS: Microscopic findings of the presumed thrombus showed prominent myxoid and edematous background with atypical spindled cells and curvilinear vascularity. Immunohistochemical staining demonstrated that the atypical spindled cells were positive for vimentin but negative for CK, S100, SMA, desmin, CD68, STAT6, CD34, ß-catenin, ALK-p80, p53, and MDM2. According to the radiological and pathological findings, the diagnosis of fibrosarcoma of pulmonary artery was made. INTERVENTIONS: The patient underwent surgical resection and the mass was excised as completely as possible. OUTCOME: Follow-up information showed no evidence of recurrence or metastasis after 3 months postresection. LESSONS: Because of the low incidence rate, nonspecific clinical symptoms, and radiological findings, primary fibrosarcoma of the pulmonary artery is commonly misdiagnosed as PTE. Pathological examination is necessary to confirm the diagnosis.