Gastric-type adenocarcinoma of the cervix in a patient with Lynch syndrome: A case report

Small Cell and Other Rare Histologic Types of Cervical Cancer

PURPOSE OF REVIEW

The goal of this paper was to summarize the recent evidence on rare subtypes of cervical cancer including small-cell carcinoma of the cervix (SCCC), gastric-type adenocarcinoma, and carcinosarcoma.

RECENT FINDINGS

All three cervical cancer subtypes are aggressive with poor treatment response and high recurrence rates. Molecular studies have identified various actionable mutations in both SCCC (PIK3CA, MYC, TP53, PTEN, ARID1A, KRAS, BRCA2) and gastric-type adenocarcinoma (KRAS, ARID1A, PTEN). While there are a limited number of case reports demonstrating a favorable response for recurrent SCCC to immune checkpoint inhibitors, a larger case series failed to show benefit. The checkpoint inhibitors role in gastric-type adenocarcinoma and carcinosarcoma is yet to be determined. Ninety-one percent of SCCC cases show PARP expression, suggesting a possible role for PARP inhibitors; however, this has yet to be examined in future clinical trials. More studies are needed, with a focus on targeted therapies. The role of PARP inhibitors in SCCC is potentially promising, but significant collaboration between centers/groups will be required to achieve this.

Gastric-type endocervical adenocarcinoma with mucoepithelial metaplasia combined with a serous borderline tumor: A case report

RATIONALE

Gastric-type endocervical adenocarcinoma (GAS) is a rare type of cervical adenocarcinoma that is a mucinous adenocarcinoma with a variety of gastral patterns. To date, there are no systematic clinical diagnosis and treatment guidelines.

PATIENT CONCERNS

In our case, a 49-year-old woman underwent pelvic magnetic resonance imaging (MRI) due to a pelvic mass, and cervical lesions were unexpectedly found. After receiving relevant surgical treatment, the pathological results showed the particularity of the tumor type-cervical gastric adenocarcinoma with a borderline serous tumor of both appendages and the right ovary.

DIAGNOSES

Postoperative routine pathological examination showed mucoepithelial metaplasia accompanied by a borderline serous tumor.

INTERVENTIONS

After gynecological/urinary ultrasound, blood tests, MRI, cervical biopsy, and uterine curettage, "robot-assisted laparoscopic radical hysterectomy + bilateral salpingectomy-ovariectomy + pelvic lymph node dissection + pelvic adhesiolysis" were performed. After the surgery, the patient was treated with radiotherapy and concurrent chemotherapy.

OUTCOMES

After the operation, radiotherapy, and chemotherapy, the patient had no tumor recurrence and is still in good condition.

LESSONS

The diagnosis of GAS is relatively difficult, its clinical manifestations lack specificity, and the pathogenesis has nothing to do with human papillomavirus infection. The patient was misdiagnosed with vaginitis at a local hospital. However, we found that MRI and pathological examination were helpful for the diagnosis of the disease. Although there are no relevant guidelines to explain the treatment principles of GAS, we believe that early surgery is conducive to the prognosis of the disease because GAS has a certain tolerance to radiotherapy and chemotherapy.

Molecular characterization of gastric-type endocervical adenocarcinoma using next-generation sequencing

Gastric-type endocervical adenocarcinoma is an uncommon aggressive type of endocervical adenocarcinoma that is not associated with human papillomavirus (HPV). At present, this tumor is classified under the spectrum of mucinous carcinoma of the uterine cervix. The clinical stage of gastric-type endocervical adenocarcinoma at the time of diagnosis is usually more advanced compared to the HPV-associated endocervical adenocarcinoma. Widespread dissemination to unusual sites, such as omentum, peritoneum, and distant organs, can be present. Owing to its rare incidence, diagnostic dilemmas, and aggressive behavior, clinical management can be challenging. In this study, we aimed to elucidate the molecular characteristics of these tumors by using next-generation sequencing (NGS) to assess 161 unique cancer-driver genes for single-nucleotide and copy-number variations, gene fusions, and insertions/deletions within gastric-type endocervical adenocarcinoma tumors. In total, 92 variants were detected across the 14 samples tested (7 variants on average per tumor). TP53 was the most recurrently mutated gene followed by MSH6, CDKN2A/B, POLE, SLX4, ARID1A, STK11, BRCA2, and MSH2. Abnormal p53 expression was observed in nine cases by immunohistochemistry, of which TP53 variants were present in four cases. MDM2 gene amplification in 12q15 (69202190-69233452) locus was seen in two cases that express normal p53 levels by immunohistochemistry. Four cases had STK11 null (frameshift/nonsense) variants, three of which were previously reported in Peutz-Jeghers syndrome. Overall, genes that are implicated in DNA damage, repair, cell cycle, Fanconi anemia pathway, and the PI3K-AKT signaling pathways were found to be mutated. Of note, genes known to have acquired and/or inherited variants in endometrial tumors were enriched within our cohort. In conclusion, our study shows the genetic heterogeneity of gastric-type endocervical adenocarcinoma with some potentially actionable molecular alterations, which highlights the importance of further molecular characterization for better identification of this rare entity, and hence better clinical management.

Recent advances in invasive adenocarcinoma of the cervix

Endocervical adenocarcinomas (ECAs) are currently classified according to the 2014 World Health Organization (WHO) system, which is predominantly based on descriptive morphologic characteristics, considers factors bearing minimal etiological, clinical, or therapeutic relevance, and lacks sufficient reproducibility. The 2017 International Endocervical Adenocarcinoma Criteria and Classification (IECC) system was developed by a group of international collaborators to address these limitations. The IECC system separates ECAs into two major groups-those that are human papillomavirus-associated (HPVA) and those that are non-HPV-associated (NHPVA)-based on morphology (linked to etiology) alone, precluding the need for an expensive panel of immunohistochemical markers for most cases. The major types of HPVA ECA include the usual (with villoglandular and micropapillary architectural variants) and mucinous types (not otherwise specified [NOS], intestinal, signet-ring, and invasive stratified mucin-producing carcinoma). Invasive adenocarcinoma NOS is morphologically uninformative, yet considered part of this group when HPV positive. NHPVA ECAs include gastric, clear cell, endometrioid, and mesonephric types. The IECC system is supported by demographic and clinical features (HPVA ECAs develop in younger patients, are smaller, and are diagnosed at an earlier stage), p16/HPV status (almost all HPVA ECAs are p16 and/or HPV positive), prognostic parameters (NHPVA ECAs more often have lymphovascular invasion, lymph node metastases, and are Silva pattern C), and survival data (NHPVA ECAs are associated with worse survival). A move from the morphology-based WHO system to the IECC system will likely provide clinicians with an improved means to diagnose and classify ECAs, and ultimately, to better personalize treatment for these patients.

Clear Cell Carcinoma of the Cervix With Choriocarcinomatous Differentiation: Report of an Extremely Rare Phenomenon Associated With Mismatch Repair Protein Abnormality

The presence of trophoblastic differentiation or nongestational choriocarcinoma in a carcinoma is rare but has been described in various organs, including in the female genital tract. We report a cervical clear cell carcinoma admixed with a component of choriocarcinoma in a 52-year-old woman, only the second report of this combination in the literature. Immunohistochemically, the tumor exhibited isolated loss of staining with the mismatch repair protein MSH6. We review the literature on trophoblastic differentiation in cervical carcinoma.

Lynch Syndrome-Related Clear Cell Carcinoma of the Cervix: A Case Report

Lynch syndrome, a hereditary cancer syndrome, occurs because of germline mutations in at least one of four DNA mismatch repair genes (MutL Homolog 1 (MLH1), MutS Homolog 2 (MSH2), MutS Homolog 6 (MSH6), and PMS1 Homolog 2 (PMS2)). The disorder is associated with colorectal, endometrial, and other epithelial malignancies, but not cervical cancer. We report a woman with Lynch syndrome with synchronous cervical cancer. This is the first report of Lynch syndrome-related clear cell carcinoma of the cervix, which indicates the possibility of an association between cervical cancer and Lynch syndrome. Suitable genetic tests are required to determine whether common genetics can account for synchronous or subsequent malignancies in Lynch syndrome patients and their families. Such knowledge will also enhance our understanding of the genetic mechanisms governing the development of apparently unrelated cancers.

Microsatellite instability-high endocervical serous carcinoma manifesting as pulmonary thromboembolism: A case report and review of the literature

A 53-year-old obese woman was referred because of sudden onset of dyspnea and chronic vaginal bleeding. In addition to severe anemia, multiple pulmonary emboli were identified. Pelvic imaging showed an irregular-shaped mass in the region of the endocervix extending to the lower uterine segment. After successful anticoagulant therapy, followed by placement of an inferior vena cava filter, transabdominal hysterectomy and bilateral salpingo-oophorectomy were performed. An immunopathological study resulted in the diagnosis of endocervical serous carcinoma. After the identification of a high level of microsatellite instability (MSI), an immunohistochemical analysis of mismatch repair (MMR) proteins showed the isolated loss of PMS2. Germline testing of MMR genes showed no mutations, indicating that the high MSI had occurred as a result of sporadic isolated loss of the PMS2 gene expression.

A Detailed Immunohistochemical Analysis of a Large Series of Cervical and Vaginal Gastric-type Adenocarcinomas

Adenocarcinomas exhibiting gastric differentiation represent a recently described and uncommon subtype of non-human papillomavirus (HPV)-related cervical adenocarcinoma. They comprise a spectrum from a well-differentiated variant (adenoma malignum/mucinous variant of minimal deviation adenocarcinoma) to a more poorly differentiated overtly malignant form, generally referred to as gastric-type adenocarcinoma. Rarely, such tumors have also been described as primary vaginal neoplasms. Gastric-type adenocarcinomas exhibit considerable morphologic overlap with adenocarcinomas originating outside the female genital tract, especially mucinous adenocarcinomas arising in the pancreas and biliary tract. Moreover, they often metastasize to unusual sites, such as the ovary and peritoneum/omentum, where they can be mistaken for metastatic adenocarcinomas from other, nongynecologic sites. There is little information regarding the immunophenotype of gastric-type adenocarcinomas, and knowledge of this is important to aid in the distinction from other adenocarcinomas. In this study, we undertook a detailed immunohistochemical analysis of a large series of cervical (n=45) and vaginal (n=2) gastric-type adenocarcinomas. Markers included were cytokeratin (CK)7, CK20, CDX2, carcinoembryonic antigen, CA125, CA19.9, p16, estrogen receptor, progesterone receptor, MUC6, PAX8, PAX2, p53, hepatocyte nuclear factor 1 beta, carbonic anhydrase IX, human epidermal receptor 2 (HER2), and mismatch repair (MMR) proteins. All markers were classified as negative, focal (<50% of tumor cells positive), or diffuse (≥50% tumor cells positive) except for p53 (classified as "wild-type" or "mutation-type"), HER2 (scored using the College of American Pathologists guidelines for gastric carcinomas), and MMR proteins (categorized as retained or lost). There was positive staining with CK7 (47/47-45 diffuse, 2 focal), MUC6 (17/21-6 diffuse, 11 focal), carcinoembryonic antigen (25/31-12 diffuse, 13 focal), carbonic anhydrase IX (20/24-8 diffuse, 12 focal), PAX8 (32/47-20 diffuse, 12 focal), CA125 (36/45-5 diffuse, 31 focal), CA19.9 (11/11-8 diffuse, 3 focal), hepatocyte nuclear factor 1 beta (13/14-12 diffuse, 1 focal), CDX2 (24/47-4 diffuse, 20 focal), CK20 (23/47-6 diffuse, 17 focal), and p16 (18/47-4 diffuse, 14 focal). Most cases were negative with estrogen receptor (29/31), progesterone receptor (10/11), PAX2 (18/19), and HER2 (25/26). p53 showed "wild-type" and "mutation-type" staining in 27 of 46 and 19 of 46 cases, respectively. MMR protein expression was retained in 19 of 20 cases with loss of MSH6 staining in 1 patient with Lynch syndrome. Molecular studies for HPV were undertaken in 2 tumors, which exhibited diffuse "block-type" immunoreactivity with p16, and both were negative. This is the first detailed immunohistochemical study of a large series of gastric-type adenocarcinomas of the lower female genital tract. Our results indicate immunophenotypic overlap with pancreaticobiliary adenocarcinomas but suggest that PAX8 immunoreactivity may be especially useful in distinguishing gastric-type adenocarcinomas from pancreaticobiliary and other nongynecologic adenocarcinomas, which are usually negative. Diffuse "block-type" p16 immunoreactivity in a cervical adenocarcinoma is not necessarily indicative of a high-risk HPV-associated tumor.

Recent Developments in Non-HPV-related Adenocarcinomas of the Lower Female Genital Tract and Their Precursors

Most adenocarcinomas in the lower female genital tract (cervix, vagina, vulva) arise in the cervix and are associated with high-risk human papillomavirus (HPV) infection. However, there is an emerging spectrum of non-HPV-related cervical adenocarcinomas, the most common of which is so-called gastric type. In this review, the concept of gastric-type cervical adenocarcinomas and their possible precursor lesions is covered, the precursor lesions still being poorly understood. Other non-HPV-related cervical adenocarcinomas are also discussed, including new information regarding molecular events in mesonephric adenocarcinoma. A variety of primary vaginal adenocarcinomas, including clear cell, endometrioid, intestinal and gastric types are also discussed. The spectrum of benign and malignant glandular lesions involving the lower female genital tract and probably derived from misplaced Skene's (periurethral) glands is also covered.