RESUMEN
Implementation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing in the daily practice of pathology laboratories requires procedure adaptation to formalin-fixed, paraffin-embedded (FFPE) samples. So far, one study reported the feasibility of SARS-CoV-2 genome sequencing on FFPE tissues with only one contributory case of two. This study optimized SARS-CoV-2 genome sequencing using the Ion AmpliSeq SARS-CoV-2 Panel on 22 FFPE lung tissues from 16 deceased coronavirus disease 2019 (COVID-19) patients. SARS-CoV-2 was detected in all FFPE blocks using a real-time RT-qPCR targeting the E gene with crossing point (Cp) values ranging from 16.02 to 34.16. Sequencing was considered as contributory (i.e. with a uniformity >55%) for 17 FFPE blocks. Adapting the number of target amplification PCR cycles according to the RT-qPCR Cp values allowed optimization of the sequencing quality for the contributory blocks (i.e. 20 PCR cycles for blocks with a Cp value <28 and 25 PCR cycles for blocks with a Cp value between 28 and 30). Most blocks with a Cp value >30 were non-contributory. Comparison of matched frozen and FFPE tissues revealed discordance for only three FFPE blocks, all with a Cp value >28. Variant identification and clade classification was possible for 13 patients. This study validates SARS-CoV-2 genome sequencing on FFPE blocks and opens the possibility to explore correlation between virus genotype and histopathologic lesions.
Asunto(s)
COVID-19/virología , Genoma Viral/genética , Pulmón/virología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , SARS-CoV-2/genética , Autopsia , COVID-19/patología , Formaldehído , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Pulmón/patología , Adhesión en Parafina , SARS-CoV-2/aislamiento & purificación , Fijación del Tejido/métodosRESUMEN
Oncologic recurrence can occur after Robot-Assisted Radical Prostatectomy. Prostate cancer metastasizes often in bones, however the peritoneum is infrequently targeted. Even more, peritoneal dissemination without any other organ involved especially the bones is very rare, only few cases are reported. Through the available literature we discuss about the presumed seeding theory leading to this atypical location for prostatic metastases. Here we report a case of isolated non-ascitic prostatic peritoneal metastases most probably due to iatrogenic spillage during surgery.