Anatomic pathology selected abstracts

in 2021 Issues, February 2021, In Every Issue

Polak SB, Van Gool IC, Cohen D, et al. A systematic review of pathological findings in COVID-19: a pathophysiological timeline and possible mechanisms of disease progression. Mod Pathol. 2020;33(11):2128–2138.

Correspondence: Dr. J. van Paassen at j.van_paassen@lumc.nl

Use of microscopic size measurements in post-neoadjuvant therapy resections of pancreatic ductal adenocarcinomas

Pancreatic ductal adenocarcinomas are increasingly being treated with neoadjuvant therapy. However, American Joint Committee on Cancer (AJCC) eighth edition T staging based on tumor size does not reﬂect treatment effect, which often results in multiple small foci of residual tumor in a background of mass-forming ﬁbrosis. The authors evaluated the performance of AJCC eighth edition T staging in predicting patient outcomes using a microscopic tumor size measurement method. They reviewed 106 post-neoadjuvant therapy pancreatectomies and measured all individual tumor foci. T stages based on gross size with microscopic adjustment (GS) and the largest single microscopic focus size (MFS) were examined in association with clinicopathological variables and patient outcomes. Sixty-three of 106 (59 percent) tumors were locally advanced; 78 percent received Folfirinox treatment. The average GS and MFS were 25 mm and 11 mm, respectively. Based on GS and MFS, respectively, nine cases each were classiﬁed as T0, 35 and 85 cases as T1, 42 and 12 cases as T2, and 20 and zero cases as T3. Higher GS- and MFS-based T stages were signiﬁcantly associated with higher tumor regression grade, lymphovascular and perineural invasion, and higher N stage. Furthermore, higher MFS-based T stage was signiﬁcantly associated with shorter disease-free survival (P< .001) and shorter overall survival (P= .002). GS was signiﬁcantly associated with overall survival (P= .046) but not with disease-free survival. The authors concluded that in post-neoadjuvant therapy PDAC resections, MFS-based T staging is superior to GS-based T staging for predicting patient outcomes, suggesting that microscopic measurements have clinical utility beyond the conventional use of GS measurements alone.

Zhang ML, Kem M, Rodrigues C, et al. Microscopic size measurements in post-neoadjuvant therapy resections of pancreatic ductal adenocarcinoma (PDAC) predict patient outcomes. Histopathol. 2020;77(1):144–155.

Correspondence: Dr. Mari Mino-Kenudson at mminokenudson@partners.org

Appendageal tumors and tumor-like lesions of the testis and paratestis

The testicular hilum and paratestis contain several embryologically diverse anatomic structures, including the spermatic cord, tunica vaginalis, epididymis, rete testis, and other embryonic remnants. A number of benign and malignant lesions arise from these morphologically distinct structures, and, owing to their proximity, it is challenging to classify and subsequently stage these tumors. The authors conducted a retrospective review of the paratesticular appendageal and rete testis tumors and tumor-like lesions diagnosed in their pathology department from 1985 through 2016. They excluded soft-tissue lesions/tumors and identified 146 paratesticular appendageal and rete testis tumors and tumor-like lesions. Most tumors were benign (n =107; 73 percent). Adenomatoid tumor (26 percent) was the most common benign tumor, followed by different types of cysts (19 percent), mesothelial hyperplasia (18 percent), serous cystadenoma (5.5 percent), and rete testis adenoma (four percent). Malignant lesions composed 23 percent of the cases, with mesothelioma being the most common (15 percent), followed by adenocarcinoma of the rete testis (four percent), serous cystadenocarcinoma (two percent), and papillary and clear cell adenocarcinoma of the epididymis (two percent). Serous borderline tumors and melanotic neuroectodermal tumor (retinal anlage tumors) composed the remaining four percent of cases. The authors concluded that a wide range of benign and malignant lesions can arise from the paratesticular region. Awareness of these lesions and their histologic spectrum is crucial to avoid diagnostic pitfalls and allows pathologists to establish a correct diagnosis and subsequent treatment plan.

Al-Obaidy KI, Alruwaii FI, Ulbright TM, et al. Appendageal tumors and tumor-like lesions of the testis and paratestis: a 32-year experience at a single institution. Hum Pathol. 2020;103:25–33. https://doi.org/10.1016/j.humpath.2020.06.006

Correspondence: Dr. Muhammad T. Idrees at midrees@iupui.edu

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