Invasive Micropapillary Carcinoma of the Uterine Cervix: Case Report of a Rare Entity

Cervical carcinomas with serous-like papillary and micropapillary components: illustrating the heterogeneity of primary cervical carcinomas

Recent changes in the classification of cervical adenocarcinomas have re-categorized serous carcinoma as potentially nonexistent. However, clinical and pathological profiles of cervical adenocarcinomas with serous-like morphological features have not been systematically evaluated using the latest taxonomy and biomarkers. We studied 14 cases of primary cervical carcinomas with serous-like morphologies (papillary and micropapillary patterns). None of these cases exhibited evidence of serous carcinoma involving the upper tracts. Patient ages ranged between 34 and 86 years, most presented with abnormal uterine bleeding. Histologically, ten cases were classified as human papillomavirus (HPV)-associated carcinomas (eight usual-type endocervical adenocarcinomas and two adenosquamous carcinomas), of which six exhibited a papillary pattern and four had a micropapillary pattern. The four remaining cases were HPV-independent gastric-type adenocarcinomas, which displayed a papillary pattern in one case and a micropapillary pattern in three others. All ten HPV-associated carcinomas displayed block positive p16 and wild-type p53 by immunohistochemistry, with nine of them confirmed by HPV testing. Two of the four gastric-type adenocarcinomas had mutation-type p53, one of which also being p16 block positive. HER2 overexpression was demonstrated in 3/14 (21.4%) cases (2 HPV-associated and 1 HPV-independent). PD-L1 expression was identified in 4/10 (40%) cases, all HPV-associated. Targeted next-generation sequencing was performed in two cases with a micropapillary pattern, revealing a missense variant in ATM in an HPV-associated tumor and missense variants in TP53 and SMARCB1 in an HPV-independent tumor. The results demonstrated that primary endocervical adenocarcinomas can mimic the appearance of serous carcinoma, while not representing serous carcinoma. Serous-like papillary and micropapillary patterns may be present in both HPV-associated and HPV-independent cervical carcinomas, but none of the cases studied were unequivocally serous upon detailed analysis. Our findings support the exclusion of "cervical serous carcinoma" from existing classifications of cervical adenocarcinoma.

Invasive Micropapillary Carcinoma of the Uterine Cervix

We herein present a case of uterine cervical invasive micropapillary carcinoma (IMPC) in a 35-year-old woman. She had neither specific symptoms nor any previous gynecological history. A cervical punch biopsy revealed a high-grade squamous intraepithelial lesion and concurrent intestinal-type mucinous carcinoma. Based on the preoperative diagnosis of endocervical adenocarcinoma, she underwent radical hysterectomy with bilateral salpingo-oophorectomy and bilateral pelvic lymph node dissection. Grossly, there was an ovoid, slightly elevated mass with surface nodularity in the lower endocervix, measuring 10 × 8 mm. Histologically, the tumor consisted predominantly of tufts of tumor cells arranged in micropapillary structures devoid of fibrovascular cores and surrounded by clear, empty, lacunar spaces between tumor cell nests and stroma. The IMPC component comprised 90% of the entire tumor volume. The greatest dimension and stromal invasion depth of the IMPC were 8 and 3 mm, respectively (FIGO stage IA2). Immunostaining revealed that mucin 1 (MUC1) surrounded each micropapillary structure, indicating the reverse epithelial polarity of the glandular cells. MUC1 was localized predominantly in the stroma-facing surface of the cell clusters, accentuating the outlines of the micropapillary structures by forming a distinct, characteristic band on this surface. In addition, targeted sequencing analysis of the IMPC revealed a missense PIK3CA mutation (c.1633G>A). In summary, we present the clinicopathological characteristics of cervical IMPC. We demonstrate for the first time that IMPC of the uterine cervix harbors a pathogenic missense mutation in PIK3CA. Further investigations using larger cohorts of patients are necessary to confirm these findings.

Micropapillary Cervical Adenocarcinoma: A Clinicopathologic Study of 44 Cases

Micropapillary adenocarcinoma has been reported as an aggressive variant of adenocarcinoma in several organs, where it is associated with poor clinical outcome. This study reports the clinicopathologic features and outcomes of cervical adenocarcinomas with a micropapillary component (micropapillary cervical adenocarcinomas); this represents the largest reported study of these neoplasms. The study comprised 44 cervical adenocarcinomas of usual (human papillomavirus-related)-type (84%), mucinous, not otherwise specified (4.5%), gastric-type (4.5%), endometrioid (4.5%), and adenosquamous carcinoma (2%). The micropapillary component comprised >50% of the neoplasm in 34 cases (77%) (group 1), and 10% to 50% in 10 cases (23%) (group 2). Lymph node metastasis was present in 41 of 44 (93%) cases and typically the nodal tumor retained a prominent micropapillary morphology. Follow-up ranged from 7 to 123 months (mean, 65.9 mo). Seventeen of 44 (38.6%) patients had no evidence of disease on follow-up, 6/44 (13.6%) were alive with disease, and 21/44 (47.7%) died of disease. There were no survival differences between group 1 and group 2. On univariate analysis, lymph node metastasis (P=0.0015), lymphovascular space invasion (P=0.002), parametrial involvement (P=0.03), and depth of stromal invasion (P=0.045) were related to tumor recurrence. On multivariate analysis, lymph node metastasis (P=0.001), and extent of lymphovascular space invasion (P=0.027) were significant independent predictors of tumor recurrence. Our study shows that a micropapillary component in cervical adenocarcinoma may be associated with aggressive behavior and that a micropapillary architecture may occur within a variety of types of cervical adenocarcinoma.

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.

Cervical Adenocarcinomas: A Heterogeneous Group of Tumors With Variable Etiologies and Clinical Outcomes

Context.—

Cervical adenocarcinomas are a heterogeneous group of tumors with varying morphologies, etiologies, molecular drivers, and prognoses, comprising approximately 25% of all cervical cancers. Unlike cervical squamous cell carcinoma, adenocarcinomas are not uniformly caused by high-risk human papillomavirus (HPV) infection and, therefore, would not necessarily be prevented by the HPV vaccine.

Objective.—

To provide a review of endocervical adenocarcinoma subtypes and, when appropriate, discuss precursor lesions, etiologies, molecular genetics, and ancillary studies within the context of clinical care. Some historical perspectives will also be provided.

Data Sources.—

Data sources included published peer-reviewed literature and personal experiences of the senior author.

Conclusions.—

Endocervical adenocarcinomas are a histologically diverse group of tumors with various causes and molecular drivers, not all related to HPV infection. Distinguishing them has important implications for treatment and prognosis as well as strategies for prevention.

Cervical carcinomas with a micropapillary component: a clinicopathological study of eight cases

AIMS

Micropapillary carcinomas, or carcinomas with a micropapillary component, are well recognised in the breast and other anatomical sites. However, they have seldom been described in the cervix. In this article, we present a clinicopathological analysis of eight cervical tumours that showed at least a focal (≥5%) component of micropapillary carcinoma.

METHODS AND RESULTS

The study group comprised eight cervical carcinomas (four adenocarcinomas and four adenosquamous carcinomas) with a micropapillary component. The median patient age was 41.5 years (range 27-65 years). At presentation, five patients were stage IB, two were stage IIB, and one was stage IV. The micropapillary component accounted for ≤25% of the tumour on initial biopsy or resection specimens in all but one case. Immunohistochemistry showed 'inside-out' (reverse polarity) mucin 1 staining along the cell membrane abutting the stroma. Four patients developed metastasis, all of whom showed a pure micropapillary pattern; this led to a misdiagnosis of an apparently independent peritoneal serous carcinoma in one case. All tumours showed diffuse p16 expression, and all three cases that were tested were positive for human papillomavirus (HPV) 18. Three of the six patients with at least 12 months of follow-up died of disease, and one is alive with distant metastasis.

CONCLUSIONS

Usual-type (HPV-related) cervical carcinomas may show micropapillary differentiation, usually as a focal finding, and the cells show reverse polarity like similar tumours arising in other sites. Micropapillary cervical carcinoma appears to be a clinically aggressive malignancy, although this needs to be confirmed in larger studies.