Trends in pathology diagnoses during 10 years of a colorectal cancer screening programme.

AIMS: We report pathology findings from the first 10 years of the faecal-occult blood-based Northern Ireland Bowel Cancer Screening Programme, presenting summary data and trends in pathology diagnoses and clinicopathological features of screen-detected cancers. METHODS AND RESULTS: Data were analysed from a comprehensive polyp-level pathology database representing all endoscopy specimens from programme inception in 2010 until 2021. A total of 9800 individuals underwent 13 472 endoscopy procedures, yielding 25 967 pathology specimens and 32 119 diagnoses. Index specimen diagnoses (4.1%) and index colonoscopies (10.4%) yielded a diagnosis of colorectal cancer, representing 1045 cancers from 1020 individuals (25 with synchronous cancers). A further 13 index cancers were identified via computed tomography colonography; 65.3% of cancer diagnoses were in males; 41.7% were stage I, 23.1% stage II, 25.8% stage III and 1.8% stage IV (7.6% unstaged). Of 233 pT1 cancers diagnosed within local excision specimens, 79 (33.9%) had completion surgery. Ten-year trends showed a steady decline in the proportion of index colonoscopies that yielded a diagnosis of cancer (14.7% in year 1; 4.8% in year 11) or advanced colorectal polyp. There was a strong upward trend in diagnoses of sessile serrated lesions, which overtook hyperplastic polyps in proportions of total index diagnoses by the end of the study time-frame (8.7% compared to 8.5%). CONCLUSIONS: Over the first 10 years of a population colorectal cancer screening programme, 'real world' pathology data demonstrate success in the form of reduced diagnoses of cancer and advanced colorectal polyp with passage of successive screening rounds. Interesting trends with respect to serrated polyp diagnoses are also evident, probably related to pathologist and endoscopist behaviour.

Impact on colorectal cancer pathology reporting practice of migration from TNM 5 to TNM 8.

AIMS: The introduction of TNM 8 into UK pathology practice in January 2018 considers tumour deposits in colorectal cancer staging for the first time. The impact of this new classification on pathology reporting practices has yet to be evaluated. METHODS AND RESULTS: A clinical audit was conducted, comparing consecutive colorectal cancer resection specimens reported under TNM 5 classification guidelines in 2017 (n = 177) and TNM 8 guidelines in 2018 (n = 234). Tumour features (venous invasion, perineural invasion, lymph node metastatic disease, tumour deposits) and changes in reporting practices were evaluated among four specialist gastrointestinal pathologists working within a large pathology department. Adoption of TNM 8 practice led to an approximate doubling in the use of ancillary stains (41.0% of TNM 8 versus 22.0% of TNM 5 cases, P < 0.001) to help evaluate tumours. A narrowing of the range between pathologists was observed in reporting cases as having one or more form of regional, extramural, discontinuous tumour (TNM 5 range = 50.0-79.0%, TNM 8 range = 57.8-65.7%), with no change in the overall proportion of cases reported as such (62.7% versus 62.4%, P = 0.95). However, significant interobserver variation in reporting rates for individual parameters remained. CONCLUSION: TNM 8 colorectal cancer staging offers potentially greater reproducibility in pathology reporting of regional, extramural, discontinuous disease with similar proportions of patients reported as having one or more of these forms of tumour spread compared with TNM 5. Further guidance in defining individual features is required to reduce interobserver variation in pathology assessments and to help elucidate the clinical significance of each parameter.

Human Papillomavirus (HPV)-associated Lymphoepithelioma-like Carcinoma of the Vagina and Anal Canal: A Rare Variant of Squamous Cell Carcinoma.

Lymphoepithelioma-like carcinoma (LELC) is an uncommon variant of squamous cell carcinoma, which is histologically identical to lymphoepithelial carcinoma of the nasopharynx. LELCs have been reported at a variety of sites, including the stomach, salivary gland, thymus, cervix, endometrium, breast, skin, bladder, and lung. We report 2 LELCs of the vagina and 1 of the anal canal, the first report of LELC at the latter site. All 3 neoplasms were diffusely positive with p16 (block-type immunoreactivity) and the anal canal lesion contained high-risk human papillomavirus type 16; the 2 vaginal neoplasms underwent human papillomavirus testing but were unsuitable for analysis. All cases were Epstein-Barr virus negative. In reporting these cases, we highlight the potential for misdiagnosis and suggest an association with human papillomavirus infection similar to LELCs in the uterine cervix.

Endometrial involvement in pseudomyxoma peritonei secondary to low-grade appendiceal mucinous neoplasm: report of 2 cases.

Pseudomyxoma peritonei is a clinical condition characterized by the presence of mucinous ascites, usually with variable amounts of neoplastic enteric-type mucinous epithelium, and most commonly secondary to spread from a low-grade appendiceal mucinous neoplasm. We report 2 cases of pseudomyxoma peritonei associated with low-grade appendiceal mucinous neoplasms where there was colonization of the endometrium (both cases) and cervical mucosa (1 case) by low-grade atypical enteric-type mucinous epithelium (CK20 positive and CK7 negative). The patients had symptoms of mucoid vaginal discharge and endometrial biopsies in both (1 patient had multiple endometrial biopsies over a period of 11 mo) and were initially interpreted as representing mucinous metaplasia. Pseudomyxoma peritonei may rarely result in endometrial and cervical mucosal involvement, presumably secondary to transtubal spread.

Do FIGO stage IA and small (≤2 cm) IB1 cervical adenocarcinomas have a good prognosis and warrant less radical surgery?

OBJECTIVES: There is a controversy regarding the optimal management of small cervical adenocarcinomas, and more radical surgery is often undertaken compared to similar size squamous carcinomas. We wished to determine the risk of parametrial involvement and metastatic disease and the outcome in International Federation of Gynecology and Obstetrics (FIGO) stage IA and small (≤2 cm) stage IB1 cervical adenocarcinomas. METHODS: All women with a diagnosis of International Federation of Gynecology and Obstetrics stages IA1, IA2, or IB1 cervical adenocarcinoma with a maximum tumor size of 2 cm were identified between 1999 and 2010 in Northern Ireland. A single pathologist reviewed all pathology prospectively at a cancer center tumor board. RESULTS: A total of 74 women were identified (mean age, 39 years; range, 25-72 years). In total, 36 women had stage IA1, 9 women had stage IA2, and 29 women had stage IB1 cervical adenocarcinomas. Surgical treatment ranged from local excision (cone or large loop excision of transformation zone) to radical hysterectomy and pelvic lymph node dissection; adjuvant therapy was not administered in any case. No parametrial involvement was seen in the 36 women who underwent parametrial resection. No lymph node metastasis was identified in the 45 women who underwent pelvic lymph node dissection. Lymphovascular space invasion was identified in 6 cases. No tumor recurrence or metastasis was noted during a mean follow-up of 35 months. CONCLUSIONS: The optimal management of women with IA or small IB1 cervical adenocarcinoma is controversial, and radical surgery is often undertaken. Our data suggest that there is an extremely low risk of parametrial and lymph node involvement with tumors 2 cm or smaller and a low recurrence rate. Less radical surgery may be warranted for small cervical adenocarcinomas, and this should be addressed by future studies.

Peritoneal bile granulomas identified at Cesarean section and mimicking disseminated malignancy.

A 37-year-old woman was found to have multiple peritoneal nodules, including on the uterine serosa, at Cesarean section. Histology showed yellow crystalline material surrounded by histiocytes and occasional multinucleate giant cells. Further enquiry revealed that the patient underwent a cholecystectomy for a perforated gallbladder 3 years earlier. Pathologists should be aware of this uncommon complication of bile leakage, which has the potential to clinically mimic disseminated malignancy. This may become increasingly common in the future since bile leakage is more likely to occur with laparoscopic than open cholecystectomy.