The new clinicopathological classification proves to be very useful in predicting the risk of recurrence of non-functioning pituitary macroadenomas after a first surgery. In particular, grade 2b lesions showed an overall likelihood of recurrence that was 8.6 times greater than those of grade 1a.

Tryptophan catabolism is used by tumors to resist immune attack. It can be catalyzed by indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO). IDO1 is frequently expressed in tumors and has been widely studied as a potential therapeutic target to reduce resistance to cancer immunotherapy. In contrast, TDO expression in tumors is not well characterized. Several human tumor cell lines constitutively express enzymatically active TDO. In human tumor samples, TDO expression has previously been detected by transcriptomics, but the lack of validated antibodies has precluded detection of the TDO protein and identification of TDO-expressing cells. Here, we developed novel TDO-specific monoclonal antibodies and confirmed by immunohistochemistry the expression of TDO in the majority of human cancers. In all hepatocarcinomas (10/10), TDO was expressed by most tumor cells. Some glioblastomas (10/39) and kidney carcinomas (1/10) also expressed TDO in tumor cells themselves but only in focal tumor areas. In addition, all cancers tested contained foci of nontumoral TDO-expressing cells, which were identified as pericytes by their expression of PDGFRβ and their location in vascular structures. These TDO-expressing pericytes belonged to morphologically abnormal tumor vessels and were found in high-grade tumors in the vicinity of necrotic or hemorrhagic areas, which were characterized by neoangiogenesis. We observed similar TDO-expressing pericytes in inflammatory pulmonary lesions containing granulation tissue, and in chorionic villi, two tissue types that also feature neoangiogenesis. Our results confirm TDO as a relevant immunotherapeutic target in hepatocellular carcinoma and suggest a proangiogenic role of TDO in other cancer types. See article by Schramme et al., p. 32

Intramedullary astrocytomas (IMAs) are rare tumors, and few studies specific to the molecular alterations of IMAs have been performed. Recently, KIAA1549-BRAF fusions and the H3F3A p.K27M mutation have been described in low-grade (LG) and high-grade (HG) IMAs, respectively. In the present study, we collected clinico-radiological data and performed targeted next-generation sequencing for 61 IMAs (26 grade I pilocytic, 17 grade II diffuse, 3 LG, 3 grade III and 12 grade IV) to identify KIAA1549-BRAF fusions and mutations in 33 genes commonly implicated in gliomas and the 1p/19q regions. One hundred seventeen brain astrocytomas were analyzed for comparison. While we did not observe a difference in clinico-radiological features between LG and HG IMAs, we observed significantly different overall survival (OS) and event-free survival (EFS). Multivariate analysis showed that the tumor grade was associated with better OS while EFS was strongly impacted by tumor grade and surgery, with higher rates of disease progression in cases in which only biopsy could be performed. For LG IMAs, EFS was only impacted by surgery and not by grade. The most common mutations found in IMAs involved TP53, H3F3A p.K27M and ATRX. As in the brain, grade I pilocytic IMAs frequently harbored KIAA1549-BRAF fusions but with different fusion types. Noncanonical IDH mutations were observed in only 2 grade II diffuse IMAs. No EGFR or TERT promoter alterations were found in IDH wild-type grade II diffuse IMAs. These latter tumors seem to have a good prognosis, and only 2 cases underwent anaplastic evolution. All of the HG IMAs presented at least one molecular alteration, with the most frequent one being the H3F3A p.K27M mutation. The H3F3A p.K27M mutation showed significant associations with OS and EFS after multivariate analysis. This study emphasizes that IMAs have distinct clinico-radiological, natural evolution and molecular landscapes from brain astrocytomas.

<b><i>Introduction:</i></b> The coronavirus disease 2019 (COVID-19) infection, caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), involves several organs through participation of angiotensin-conversion enzyme 2 (ACE2) receptors. The presence of ACE2 receptors in the liver renders this organ a potential target for the novel coronavirus. <b><i>Methods:</i></b> We performed 14 complete autopsies of patients infected with SARS-CoV-2. In each case we stained liver tissue sections with haematoxylin/eosin, Masson blue trichrome stain, periodic acid-Schiff (PAS), Perls, and performed cytokeratin-7 (CK7) immunochemistry. <b><i>Results:</i></b> Macroscopically, livers were pale and yellowish in 8 of 14 (57%) patients, and had a nutmeg appearance in the other 6 cases (42%). Histologically, centrolobular necrosis was observed in 12 cases (86%), and was associated with discreet to moderate lobular or portal inflammation. Steatosis was seen in 8 cases (57%), but fibrosis was rare. Cholestasis and discrete bile duct proliferation was observed in 5 cases (36%). <b><i>Discussion/Conclusion:</i></b> The main histological changes can be explained by the hypoxic status as a result of severe hypoxemic pneumonia leading to death. Drug toxicity may also play a role in certain cases. Other histological changes may be explained by previous hepatic conditions or underlying hepatic diseases. We concluded that COVID-19 infection was not associated with a specific histopathological pattern of the liver.