Anatomic pathology selected abstracts

Create PDF

Editors: Rouzan Karabakhtsian, MD, PhD, professor of pathology and director of the Women’s Health Pathology Fellowship, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY; Shaomin Hu, MD, PhD, staff pathologist, Cleveland Clinic; S. Emily Bachert, MD, breast pathology fellow, Brigham and Women’s Hospital, Boston; and Amarpreet Bhalla, MD, assistant professor of pathology, Albert Einstein College of Medicine, Montefiore Medical Center.

Rare cases of intraductal adenocarcinoma of prostate with cribriform or papillary ductal morphology

December 2022—Prostatic duct adenocarcinoma, which is characterized by pseudostratified columnar epithelium, has historically been considered invasive carcinoma, although it may have an intraductal component. Usual (acinar) intraductal carcinoma of the prostate (IDC-P) is a noninvasive high-risk lesion typically associated with high-grade, high-stage prostate cancer. While biopsy studies of pure acinar IDC-P or IDC-P associated with only low-grade carcinoma have been rare, there have been no analogous series of IDC-P with cribriform or papillary ductal morphology on biopsy that were not associated with invasive high-grade carcinoma. The authors conducted a study in which they identified 14 patients with biopsies showing IDC-P with ductal morphology, defined as prostatic duct adenocarcinoma confined to glands or ducts with immunohistochemically proven retention of basal cells. Twelve patients had pure IDC-P and two had concurrent low-volume grade group one invasive cancer in unassociated cores. Three patients underwent radical prostatectomy: Two of the three had high-grade cancer in their resection specimens (grade groups three and five), including one with advanced stage and nodal metastases, and one of the three had grade group one organ-confined carcinoma and spatially distinct IDC-P with ductal morphology. Five patients had only follow-up biopsies: Two of the five had cancer (grade groups two and four); one of the five had IDC-P (on two repeat biopsies); and two of the five had benign transurethral resection of the prostate. In all five cases with invasive cancer, the invasive portion was composed solely of acinar morphology—no invasive ductal component was identified. Five patients did not have follow-up biopsies and were treated with radiation therapy with or without androgen deprivation. No follow-up information was available for one patient. In a situation analogous to that involving acinar IDC-P, the authors suggested that there is rarely a precursor form of ductal adenocarcinoma that can exist without concurrent invasive high-grade carcinoma. They proposed the term “IDC-P with ductal morphology,” consistent with the terminology for acinar prostate adenocarcinoma. Until more evidence is accumulated, they recommend reporting and treating patients with IDC-P with ductal morphology in a manner analogous to that for acinar IDC-P. As with pure IDC-P with acinar morphology, the authors recommend not grading pure IDC-P with ductal morphology. Furthermore, they propose expanding the diagnostic criteria of IDC-P to include intraductal lesions with ductal morphology consisting of papillary fronds or cribriform lesions lined by cytologically atypical pseudostratified epithelium.

Russell DH, Epstein JI. Intraductal adenocarcinoma of the prostate with cribriform or papillary ductal morphology: Rare biopsy cases lacking associated invasive high-grade carcinoma. Am J Surg Pathol. 2022;46(2):233–240.

Correspondence: Dr. Daniel H. Russell at drusse29@jh.edu

Findings in tissue obtained from gender-affirming gynecologic surgery

Gender-affirming surgery is part of a multidisciplinary approach in gender transitioning. Deeper histologic examination may improve care for transmasculine people and increase understanding of how hormonal therapy affects specific organs. The authors conducted a study to evaluate and catalog histologic findings from tissue obtained from gender-affirming gynecologic surgery and cervical cytology specimens. The institutional review board-approved retrospective study included transmasculine people who underwent gender-affirming gynecologic surgery from January 2015 to June 2020. Two pathologists reviewed all surgical gynecologic pathology and cervical cytology slides. The study included 55 patients who represented 40 uteri, 35 bilateral ovaries, 15 vaginectomy specimens, and 24 cervical cytology results. The study participants were a median age of 27 years (range, 18–56 years) and 94 percent (50 of 53) of them had been receiving testosterone for at least one year. The authors found that 75 percent (30 of 40) of endometria were inactive, while 25 percent (10 of 40) showed evidence of cycling. Transitional cell metaplasia was the most common finding in the cervix (43 percent; 17 of 40) and vagina (100 percent; 15 of 15), reflecting 17 percent (4 of 24) of unsatisfactory or atypical squamous cells of undetermined significance (ASCUS) cervical cytologies. Prostatic-type glands were identified in 20 percent (8 of 40) of cervices and 67 percent (10 of 15) of vaginectomy specimens. Multiple bilateral cystic follicles and evidence of follicular maturation were present in 57 percent (20 of 35) of cases. Ten percent (4 of 40) of cases showed paratubal epididymis-like mesonephric remnant hypertrophy. The authors concluded that a comprehensive evaluation of tissue from gender-affirming surgery increases knowledge of the changes following androgen therapy in transmasculine people and may contribute to optimal patient care by raising awareness of normal histologic variations in this population.

Lin LH, Hernandez A, Marcus A, et al. Histologic findings in gynecologic tissue from transmasculine individuals undergoing gender-affirming surgery. Arch Pathol Lab Med. 2022;146(6):742–748.

Correspondence: Dr. Lawrence Hsu Lin at lawrencehlin@gmail.com

Validation of a modified scheme for subcategorizing salivary gland neoplasm of uncertain malignant potential

The category of salivary gland neoplasm of uncertain malignant potential (SUMP) in the Milan System for Reporting Salivary Gland Cytopathology is diagnostically challenging. The authors conducted a study to validate a modified scheme for subcategorizing SUMP in a large multi-institutional cohort. Retrospective reviews of salivary gland fine-needle aspirations (FNAs) from 10 institutions were classified based on the Milan system. The cases of patients who were diagnosed with SUMP and who had cytology slides available, as well as surgical follow-up, were retrieved for review and subcategorized based on a modified scheme. The cases were subcategorized as basaloid SUMP (B1: absent/scant nonfibrillary matrix; B2: presence of nonfibrillary/mixed-type matrix), oncocytic/oncocytoid SUMP (O1: with mucinous background; O2: without mucinous background), and SUMP not otherwise specified (NOS). A total of 742 (7.5 percent) cases from 9,938 consecutive salivary gland FNAs were classified as SUMP. Of that group, 525 (70.8 percent) had surgical follow-up, and 329 (62.7 percent) of the latter cases were available for review. The overall risk of malignancy for SUMP was 40.4 percent. A total of 156 (47.4 percent) cases were subcategorized as basaloid SUMP with a risk of malignancy of 36.5 percent, 101 (30.7 percent) as oncocytic/oncocytoid SUMP with a risk of malignancy of 52.5 percent, and 72 (21.9 percent) as SUMP NOS with a risk of malignancy of 31.9 percent. The risk of malignancy for oncocytic/oncocytoid SUMP was significantly higher than that for basaloid SUMP (P=0.0142) and SUMP NOS (P=0.0084). No significant differences in risk of malignancy were noted between B1 and B2 (36.7 versus 36.4 percent; P=1.0000) and O1 and O2 (65.2 versus 48.7 percent; P=0.2349). The risk of malignancy for oncocytic/oncocytoid SUMP was 52.5 percent, significantly higher than that for basaloid SUMP (36.5 percent; P=0.0142) and SUMP NOS (31.9 percent; P=0.0084). No significant differences in risk of malignancy were noted for cases with different types of extracellular matrices or background material. Based on their findings, the authors requested that an update of the diagnostic criteria for subcategorizing SUMP be considered for the second edition of the Milan system.

Hang JF, Lee JJL, Nga ME, et al. Multi-institutional validation of a modified scheme for subcategorizing salivary gland neoplasm of uncertain malignant potential (SUMP). Cancer Cytopathol. 2022;130:511–522.

Correspondence: Dr. Varsha Manucha at vmanucha@umc.edu

Use of an infiltration-pattern scoring system to assess pancreatic neuroendocrine tumors

The advancing edge profile is a powerful determinant of tumor behavior in many organs. The authors developed a system for scoring the invasiveness at the advancing edge of pancreatic neuroendocrine tumors (PanNETs) and correlated the classification system with the clinicopathologic features of aggressiveness in PanNETs. The grading system was tested on 181 PanNETs, 63 of which were 2 cm or less. Three tumor slides representative of the spectrum of invasiveness (least, medium, and most) at the advancing edge of the tumor were selected by evaluating the slides with tumors using the naked eye. Then the infiltration patterns were evaluated under the microscope and ranked for the three selected slides for each case. The slides were scored as well demarcated/encapsulated (one point); mildly irregular borders or minimal infiltration into adjacent tissue, or both (two points); infiltrative edges with several clusters beyond the main tumor but still relatively close or satellite demarcated nodules, or both (three points); no demarcation, several cellular clusters away from the tumor (four points); or exuberantly infiltrative pattern, scirrhous growth, dissecting the normal parenchymal elements (five points). Based on the sum of the grades for the three slides, cases were placed into categories. Cases with scores of three to six were defined as non/minimally infiltrative (NI; n=77), while scores of seven to nine were moderately infiltrative (MI; n=68) and 10 to 15 were highly infiltrative (HI; n=36). In addition to showing a statistically significant correlation with the established signs of aggressiveness, such as tumor grade and T stage, this grading system was found to be the most significant predictor of adverse outcomes (metastasis, progression, and death) on multivariate analysis—more so than T stage and Ki-67 index. Just as importantly, tumors of 2 cm or less were stratified by this grading system, making the system useful for the watchful-waiting approach. The authors concluded that the proposed grading system has a strong, independent prognostic value. Therefore, it should be evaluated in validation studies with larger series as part of a process to consider whether it should be integrated into routine pathology practice.