Tall cell carcinoma of the breast with reversed polarity - a report of three cases with a review of the literature.

Tall cell carcinoma with reverse polarity (TCCRP) is a rare special type of breast epithelial neoplasm presented by columnar cells with opposite nuclear polarity, solid and solid-papillary architecture, and frequent IDH2 gene alterations. Hereby, the authors present three cases of TCCRP in women aged 56, 66 and 67 years with maximum tumour sizes of 29 mm, 10 mm and 8 mm. Tumours showed histomorphological characteristics of TCCRP supported by immunohistochemical profile of tumour cells, in which positive expression of CK7, CK5/6, GCDFP15, mammaglobin, GATA3 and calretinin and negativity of CK14, p63, TTF1, thyroglobulin and neuroendocrine markers were demonstrated. Two tumours were triple negative, and in one tumour, only weak focal ER expression was noted along with PR and HER2 negativity. Pathogenic somatic variants in mutational hotspot region p.R172 in IDH2 gene were detected using NGS technology in all three tumours. Moreover, in two of these tumours, the most common pathogenic variants p.E545A and p.H1047R of PIK3CA were identified. TCCRP represents a rare breast neoplasm of low malignant potential, the incidence of which will probably increase due to the more clearly defined histomorphological, immunohistochemical and molecular-genetic characteristics, which were all responsible for including this entity into the 5th edition of WHO classification breast tumours.

Cystic trophoblastic tumour of the testis: Case report.

Cystic trophoblastic tumor (CTT) is a rare non-aggressive germinative neoplasm from the group of non-choriocarcinomatous trophoblastic tumors, which is presented by cystic spaces lined with mononuclear degenerative-looking trophoblastic cells. CTT has been most often described as a residual disease in dissected retroperitoneal lymph nodes of patients with metastatic germ cell testicular tumours after chemotherapy. There were published only sporadic cases of primary testicular mixed germ cell tumour with CTT component. Hereby, the authors present a case of a 22-year-old man with a mixed germ cell tumour composed of postpubertal teratoma, embryonal carcinoma and CTT. Immunohistochemically, the CTT tumour cells were positive for cytokeratins (AE1/AE3, CK8/18), GATA3, p63 and focally also for beta-hCG and alpha-inhibin. CTT may be presented as a rare component of primary testicular mixed germ cell tumour and it represents very likely an evolutionary intermediate stage of transition from choriocarcinoma into teratoma during the process of regression.

Acute kidney rejection after anti-SARS-CoV-2 virus-vectored vaccine-case report.

COVID-19 infection remains a threat to the health systems of many countries. Potential success in the fight against the COVID-19 pandemic is the vaccination of high-risk groups, including patients with end-stage kidney disease (ESKD) and after solid organ transplantation (SOT). Immunosuppression in kidney transplant recipients can also reduce the immunogenicity of SARS-CoV-2 vaccines (varied by vaccine platform), available data suggest that they are efficacious in approximately 50-70%, compared to non-transplant situations. In this paper, we present a newly developed acute humoral and cellular rejection with acute allograft failure and need of hemodialysis 14 days after administration of the adenovirus vectored SARS-CoV-2 vaccine (AstraZeneca; CHADOx1, AZD1222). This occurred in a patient who previously had an asymptomatic COVID-19 infection. Case reports of acute allograft rejection after vaccination against SARS-CoV-2 can help stratify risk groups of patients who develop hyperimmune reactions. However, it is also possible that those with a previous mild primary COVID-19 infection may also develop acute allograft rejections upon COVID-19 re-infection.