Uterine perivascular epithelioid cell neoplasms (PEComas): report of two cases and literature review.

Perivascular epithelioid cell tumors (PEComas) are rare tumors characterized by co-expression of melanocytic and smooth muscle markers. PEComas have been reported in a wide variety of anatomic sites. In the female genital tract, PEComas most frequently affect the uterus. PEComas which occur in non-classic anatomic distributions are known as perivascular epithelioid cell tumor-not otherwise specified (PEComa-NOS). PEComas have an unpredictable biologic behavior, with some tumors being unresectable or metastatic at the time of diagnosis. The risk of aggressive behavior of these tumors has been linked to a number of factors evaluable on histopathological review following initial surgical resection. The authors report two cases of PEComa-NOS of the uterus: one with disease confined to uterus and the other case with lung and liver metastasis.

Squamous cell carcinoma arising in mature cystic teratoma of the ovary: report of two cases with molecular analysis.

Mature cystic teratoma (MCT) is the most frequent ovarian tumor and it is generally composed of well-differentiated elements which, nevertheless, have the potential for malignant transformation. The authors report two cases of squamous cell carcinoma (SCC) arising on ovarian MCT. In the present study, no mutation of the CDKN2A gene, whose impairment may deeply affect either the p16(CDKN2A)-CyclinD1-pRb cascade or the p14(CDKN2A)-mdm2-p53 cascade, was observed in tumour tissues from our cases' collection. This suggests that changes in the protein levels for the above-described candidate effectors may be somehow due to epigenetic alterations into the mechanisms controlling their expression. Analogously, no genetic modification among the two main genes (EGFR and KRAS) upstream the MAPK signalling pathway, which has been widely reported to play a major role in both development and progression of vast majority of malignant tumours, was detected in this series. Additional genes and pathways should be therefore investigated in order to identify genomic impairments underlying the MCT malignant transformation.

Hybrid transanal endoscopic microsurgery: a novel approach to rectal neoplasm excision.

AIM: Rectal neoplasm excision is a challenging issue in gastrointestinal endoscopy and surgery. This technical note describes a hybrid method for the excision of challenging rectal neoplasms. METHOD: The procedure consists of the combined use of classic endoscopy and transanal endoscopic microsurgical instrumentation for full-thickness removal of a recurrent rectal polyp in a patient who had previously undergone endoscopic excision of a Tis rectal adenocarcinoma, located behind the valve of Houston and 9 cm from the anal verge. RESULTS: The lesion was removed completely in 50 min with no operative complication. The patient's postoperative course was uneventful, and she was discharged after 5 days. Pathological examination of the specimen confirmed complete resection of the lesion with adequate disease-free margins. CONCLUSION: Hybrid transanal endoscopic microsurgery successfully combines the precision and flexibility of classic endoscopy with the radicality and safety of transanal endoscopic microsurgery for the treatment of demanding benign or early-stage malignant rectal tumours.

Immunoreactivity for Ca 125 and INI 1 loss of expression are useful markers in the diagnosis of vulvar proximal-type epithelioid sarcomas: report of two cases.

Epithelioid sarcomas (ES) are rare soft tissue tumours of obscure histogenesis. Diagnosis is often difficult as specific morphological and immunohistochemical patterns do not exist. Two distinct clinico-pathological entities have been identified: the classic or distal type and the proximal type. Recently, immunohistochemical detection of Ca 125 was described in ES, as well as loss of INI 1 expression. The authors describe in this paper the morphological and immunohistochemical features of two cases of proximal ES of the vulva. Immunoreactivity for Ca 125 and loss of INI 1 expression were present in both cases. These results confirm previous observations in Asian reports showing that these markers can be used as immunohistochemical markers for the diagnostic assessment of ES.

A meta-regression study of the clinical significance of serum aminotransferases in COVID-19.

OBJECTIVE: The aim of the study was to appraise the capacity of serum aminotransferases to discriminate between hepatic and other extra-pulmonary COVID-19-related manifestations and, potentially, to serve as predictors of poor clinical outcomes. MATERIALS AND METHODS: Ninety-eight studies were identified (79% from China), including 43,554 patients (57% males), 9,983 (62% males) with poor outcomes and 33,571 (50% males) with favorable outcomes. After splitting studies depending on whether serum alanine aminotransferase (ALT) concentrations were statistically different between patients with poor vs. favorable outcomes, the 35 'hepatic involvement' articles (p<0.05) included 28,510 patients (51% males), 5,279 (66% males) and 23,231 subjects (48% males) with poor and favorable outcomes, respectively. The 63 'extra-hepatic involvement' studies (p>0.05) included 15,044 patients (54% males), 4,704 (60% males) with poor outcomes and 10,340 (51% males) with favorable outcomes. RESULTS: The meta-analysis shows that serum aspartate aminotransferase (AST) concentrations were significantly higher in patients with poor outcomes than those with favorable outcomes (WMD 12.5 UI/L, 95% CI 10.9 to 14.1 p<0.001). Similarly, AST concentrations were significantly higher in the 'hepatic involvement' studies (WMD 16.3 UI/L, 95% CI 13.4 to 19.2 p<0.001) and in the 'extra-hepatic involvement' studies (WMD 10.3 UI/L, 95% CI 8.6 to 12.0 p<0.001). CONCLUSIONS: The different association of serum AST concentrations with some clinical, demographic, and biochemical factors in the two clusters suggests that in COVID-19 patients, serum AST elevation is not necessarily linked to real liver damage.

Impact of novel histopathological factors on the outcomes of liver surgery for colorectal cancer metastases.

INTRODUCTION: We evaluated the impacts of a series of novel histopathological factors on clinical-surgical outcomes and survival of patients who underwent surgery for colorectal cancer liver metastasis, with and without neoadjuvant chemotherapy. MATERIALS AND METHODS: A prospective database including 150 consecutive patients who underwent 183 hepatic resections for metastatic colorectal cancer was evaluated. Among them, 74 (49.3%) received neoadjuvant chemotherapy before surgery. The histopathological factors studied were: a) microsatellitosis, b) type and pattern of tumour growth, c) nuclear grade and the number of mitoses/mm(2), d) perilesional pseudocapsule, e) intratumoural fibrosis, f) lesion cellularity, g) hypoxic-angiogenic perilesional growth pattern, and h) the tumour normal interface. RESULTS: Three or more metastatic lesions, R1 resection margins, and <50% tumour necrosis were prognostic factors for a worse OS, but only the former was confirmed to be an independent prognostic factor in the multivariate analysis. Furthermore, tumour fibrosis <40% and cellularity >10% were predictive of a worse neoadjuvant therapy response, but these findings were not confirmed in the multivariate analysis. Finally, tumour necrosis <50%, cellularity >10%, and TNI >0.5 mm were prognostic factors for a worse DFS and AS in the univariate but not in the multivariate analysis. CONCLUSIONS: Several factors seem to influence the outcomes of surgery for colorectal cancer liver metastasis, especially the number of the lesions, the margins of resection, the percentage of necrosis and fibrosis, as well as the cellularity and the TNI.

Nonfunctional paraganglioma of the head of the pancreas: A rare case report.

BACKGROUND: Paragangliomas are rare neoplasms that originate from the neural crest. They are malignant in approximately 10% of cases, with a 50% survival rate at 5 years from diagnosis. In most cases, manifestations of malignancy (such as metastasis) are lacking, and paragangliomas are considered benign lesions. Pancreatic paragangliomas are extremely rare, with only 31 cases described in the scientific literature to date. CASE SUMMARY: Here we describe a case of a 55-year-old Caucasian male patient referred to our institution in September 2013 for lumbar pain lasting five months. The ultrasound and the CT scan revealed a 2.5cm solid nodule located in the uncinate process of the pancreas. On the basis of this evidence, the preoperative diagnosis was a pancreatic neuroendocrine tumor (NET), which was further confirmed by a subsequent In-Pentetreotide Scan examination. A pylorus-preserving duodenocephalopancreasectomy was performed. Pancreatic paraganglioma was the final pathological diagnosis. Rare localizations of paraganglioma are often discovered casually, during imaging examinations for other clinical reasons, as happened in the case of our patient. It appears evident that the preoperative diagnosis of pancreatic paragangliomas is extremely challenging. Surgery represents the cornerstone of the clinical management of these neoplasms, primarily for the need of a definitive diagnosis, which is difficult to assess preoperatively in most cases. CONCLUSIONS: Our strategy is the same as that adopted for the management of pancreatic NETs; the dimensional limit for a conservative resection is 2cm, while major resections (Whipple's approach or distal pancreatectomy) should be employed in larger tumors, which are generally associated with a worse prognosis.

TET1 is a tumour suppressor that inhibits colon cancer growth by derepressing inhibitors of the WNT pathway.

Ten eleven translocation (TET) enzymes catalyse the oxidative reactions of 5-methylcytosine (5mC) to promote the demethylation process. The reaction intermediate 5-hydroxymethylcytosine (5hmC) has been shown to be abundant in embryonic stem cells and tissues but strongly depleted in human cancers. Genetic mutations of TET2 gene were associated with leukaemia, whereas TET1 downregulation has been shown to promote malignancy in breast cancer. Here we report that TET1 is downregulated in colon tumours from the initial stage. TET1 silencing in primary epithelial colon cells increase their cellular proliferation while its re-expression in colon cancer cells inhibits their proliferation and the growth of tumour xenografts even at later stages. We found that TET1 binds to the promoter of the DKK gene inhibitors of the WNT signalling to maintain them hypomethylated. Downregulation of TET1 during colon cancer initiation leads to repression, by DNA methylation, the promoters of the inhibitors of the WNT pathway resulting in a constitutive activation of the WNT pathway. Thus the DNA hydroxymethylation mediated by TET1 controlling the WNT signalling is a key player of tumour growth. These results provide new insights for understanding how tumours escape cellular controls.