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Coronavirus disease 2019 (COVID-19) is a global public health emergency with many clinical facets, and new knowledge about its pathogenetic mechanisms is deemed necessary; among these, there are certainly coagulation disorders. In the history of medicine, autopsies and tissue sampling have played a fundamental role in order to understand the pathogenesis of emerging diseases, including infectious ones; compared to the past, histopathology can be now expanded by innovative techniques and modern technologies. For the first time in worldwide literature, we provide a detailed postmortem and biopsy report on the marked increase, up to 1 order of magnitude, of naked megakaryocyte nuclei in the bone marrow and lungs from serious COVID-19 patients. Most likely related to high interleukin-6 serum levels stimulating megakaryocytopoiesis, this phenomenon concurs to explain well the pulmonary abnormal immunothrombosis in these critically ill patients, all without molecular or electron microscopy signs of megakaryocyte infection.

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This article is protected by copyright. All rights reserved. Background: Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) share clinical, pathological, immunohistochemical and molecular features, though PDS is associated with a more aggressive behavior. Methods: We revised 71 tumors fulfilling criteria for AFX and PDS to further stratify their biological potential. Results: Lesions predominate on the scalp of elderly men, were frequently ulcerated, one case presented necrosis, one vascular, and another perineural invasion. Fifty-one tumors were limited to reticular dermis (71.8%), 20 invaded subcutaneous tissue, focally in 13 cases (18.3%), and diffusely in seven (9.9%). A significant more frequent subcutaneous invasion was observed in tumors showing predominantly spindle compared to pleomorphic/mixed cell morphology (p= 0.02). At a follow-up of 17-125 months, 4 cases recurred locally, 4, 6, 10 and 13 months after surgery; no metastases were observed. Three tumors were composed of spindle cells, and one of clear cells. Three cases had margins focally involved, the fourth case had clear margins. Conclusion: Depth of invasion and state of margins are criteria predicting prognosis in AFX/PDS; in addition, spindle cell morphology seems to be related to a more infiltrative pattern of growth and consequently aggressiveness. Grouping these tumors on a morphologic base could contribute to clarify their different biological behavior.

Prognosis of gastric cancer is dramatically improved by early diagnosis. Correa’s cascade correlates the expression of some molecular markers with the progression of preneoplastic lesions toward carcinoma. This article reviews the diagnostic and prognostic values of molecular markers in complete (MUC2) and incomplete (MUC2, MUC5AC, and MUC6) intestinal metaplasia, gastric dysplasia/intra-epithelial neoplasia, and early gastric cancer. In particular, considering preinvasive neoplasia and early gastric cancer, some studies have demonstrated a correlation between molecular alterations and prognosis, for example, mucins phenotype in gastric dysplasia, and GATA6, TP53 mutation/LOH and MUC6 in early gastric cancer. Moreover, this review considers novelties from the literature regarding the (immuno)histochemical characterization of diffuse-type/signet ring cell gastric cancer, with particular attention to clinical outcomes of patients. The aim of this review is the evaluation of the state of the art regarding suitable biomarkers used in the pre-surgical phase, which can distinguish patients with different prognoses and help decide the best therapeutic strategy.