High-grade Neuroendocrine Carcinomas of the Vulva: A Clinicopathologic Study of 16 Cases

Small-cell neuroendocrine carcinoma of the female genital tract: A comprehensive overview

Small-cell neuroendocrine carcinomas (SCNECs) of the female genital tract are rare and aggressive tumors that are characterized by a high rate of recurrence and poor prognosis. They can arise from various sites within the female genital tract, including the cervix, endometrium, ovary, fallopian tube, vagina, and vulva. They are composed of cells with neuroendocrine features, such as the ability to produce and secrete hormones and peptides, and a high mitotic rate. Immunohistochemical staining for neuroendocrine markers, such as chromogranin A, synaptophysin, and CD56, can aid in the diagnosis of these tumors. This article provides an overview of the epidemiology, etiology, and risk factors associated with these tumors, as well as their clinical presentation, cellular characteristics, diagnosis, and finally the current treatment options for SCNECs, including surgery, chemotherapy, and radiation therapy, alone or in combination.

Primary neuroendocrine neoplasms of the vulva: A review of the MITO rare cancer group

Gynecological neuroendocrine neoplasms are rare entities and can be divided into two groups: carcinoids and neuroendocrine carcinomas. Due to their rarity their management is not standardized. The aim of this work is to summarize and discuss the current literature evidence on this pathology. A scoping literature review was performed in multiple databases. Thirty-one studies were included: 30 case reports and one case series. Patients' age ranged between 28 and 92 years. Surgery was the most used treatment and the surgical approach included local excision (N = 16/31; 51.6%) with (N = 5/16; 31.25%) or without (N = 11/16; 68.75%) inguinal lymphadenectomy. Adjuvant radiotherapy was delivered in 12 (38.7%) cases; instead, platinum-based therapies were frequently used when chemotherapy was chosen for adjuvant treatment. The overall survival ranged between 20 days to 4 years. However, further research is needed; currently, multimodal approach including surgery, chemotherapy and radiotherapy appeared safe and feasible for the treatment of these rare and aggressive diseases.

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.

Feline papillomavirus-associated Merkel cell carcinoma: a comparative review with human Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare skin tumor that shares a similar immunophenotype with Merkel cells, although its origin is debatable. More than 80% of human MCC cases are associated with Merkel cell polyomavirus infections and viral gene integration. Recent studies have shown that the clinical and pathological characteristics of feline MCC are comparable to those of human MCC, including its occurrence in aged individuals, aggressive behavior, histopathological findings, and the expression of Merkel cell markers. More than 90% of feline MCC are positive for the Felis catus papillomavirus type 2 (FcaPV2) gene. Molecular changes involved in papillomavirus-associated tumorigenesis, such as increased p16 and decreased retinoblastoma (Rb) and p53 protein levels, were observed in FcaPV2-positive MCC, but not in FcaPV2-negative MCC cases. These features were also confirmed in FcaPV2-positive and -negative MCC cell lines. The expression of papillomavirus E6 and E7 genes, responsible for p53 degradation and Rb inhibition, respectively, was detected in tumor cells by in situ hybridization. Whole genome sequencing revealed the integration of FcaPV2 DNA into the host feline genome. MCC cases often develop concurrent skin lesions, such as viral plaque and squamous cell carcinoma, which are also associated with papillomavirus infection. These findings suggest that FcaPV2 infection and integration of viral genes are involved in the development of MCC in cats. This review provides an overview of the comparative pathology of feline and human MCC caused by different viruses and discusses their cell of origin.

Cutaneous Neuroendocrine Mucinous Carcinomas Are Low-grade But May Be Associated With Other Cancers

Primary cutaneous mucinous sweat gland carcinoma is said to be prognostically stratifiable by neuroendocrine differentiation, however, this assertion is based on historical data and older staining techniques. We aimed to evaluate the percentage of mucinous and nonmucinous adnexal tumors expressing the newer, more sensitive neuroendocrine marker insulinoma-associated protein 1 (INSM1), and to assess clinicopathologic features in patients cohorted by this phenotype. Of 12 available adnexal/cutaneous adenocarcinomas, 9 were mucinous, 3/9 of which were INSM1-negative, and 2/3 with nodal metastases. Of 3 nonmucinous cases, all were INSM1-negative, 1/3 with nodal metastasis, and 2/3 with lymphovascular invasion. In contrast, of 6 mucinous INSM1-positive cases, no cases had LVI or metastasis, however, 3 patients died during follow-up, 2 from breast or urothelial cancer. A fourth patient developed breast carcinoma. INSM1-positive tumors, from cheek (3), scalp (2), and chin (1) were estrogen receptor and progesterone receptor positive. No cases of apocrine adenoma or hidrocystoma, basal cell, or sebaceous carcinoma labeled with INSM1. While most primary cutaneous mucinous carcinomas are of the neuroendocrine type, our study confirms the presence of occasional non-neuroendocrine mucinous carcinomas. We validate the association of such tumors and nonmucinous non-neuroendocrine adnexal carcinoma with intermediate-grade behavior, including lymph node metastases, but not death. Conversely, neuroendocrine expressing primary cutaneous mucinous carcinoma may represent the well-differentiated neuroendocrine neoplasm/neuroendocrine tumor primary to skin, with low-grade behavior, but attendant risk of germline susceptibility to other aggressive extracutaneous tumors. Routine assessment of cutaneous adnexal carcinoma with INSM1 and longer term follow-up and cancer screening of patients with positive staining is recommended.

Data Set for the Reporting of Carcinomas of the Vulva: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

A cogent and comprehensive pathologic report is essential for optimal patient management, cancer staging, and prognostication. This article details the International Collaboration on Cancer Reporting (ICCR) process and the development of the vulval carcinoma reporting data set. It describes the "core" and "noncore" elements to be included in pathology reports for vulval carcinoma, inclusive of clinical, macroscopic, microscopic, and ancillary testing considerations. It provides definitions and commentary for the evidence and/or consensus-based deliberations for each element included in the data set. The commentary also discusses controversial issues, such as p16/human papillomavirus testing, tumor grading and measurements, as well as elements that show promise and warrant further evidence-based study. A summary and discussion of the updated vulval cancer staging system by the International Federation of Obstetricians and Gynaecologists (FIGO) in 2021 is also provided. We hope the widespread implementation of this data set will facilitate consistent and accurate reporting, data collection, comparison of epidemiological and pathologic parameters between different populations, facilitate research, and serve as a platform to improve patient outcomes.

Neuroendocrine Neoplasia of the Female Genital Tract

Neuroendocrine neoplasia is relatively uncommon in the female genital tract (FGT) and occurs at any site, most often the ovary and cervix. A unified dichotomous nomenclature, introduced by the World Health Organization Classification of Tumors in all fifth edition volumes, divides neuroendocrine neoplasms (NENs) into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The term carcinoid tumor is retained in the ovary and represents the commonest FGT NEN. NEC is most common in the cervix and is usually admixed with another human papillomavirus-associated epithelial neoplasm. Despite shared neuroendocrine differentiation, NET and NEC show diverse etiology, morphology, and clinical behavior.

Vulvar neuroendocrine carcinoma that is independent of merkel cell polyomavirus and human papillomavirus suggests endometrial cancer recurrence: a case report

BACKGROUND

Vulvar neuroendocrine carcinomas with small cell morphology need an appropriate differential diagnosis with respect to primary Merkel cell carcinomas, primary small cell neuroendocrine carcinomas, and secondary/metastatic carcinomas. Herein, we report a woman with a history of endometrial carcinoma led to neuroendocrine vulvar carcinoma.

CASE PRESENTATION

An 82-y-old woman with right vulvar swelling was transferred to our hospital. Computed tomography scan showed a 75 mm irregular mass in her right vulva. Three years ago, she had been diagnosed with endometrial endometrioid carcinoma stage IA and had undergone surgery. Vulvar biopsy revealed neuroendocrine carcinomas with small cell morphology. Immunohistochemical staining showed that the vulvar tumor was positive for CD56 and chromogranin A, but negative for Merkel cell polyomavirus and cytokeratin 20. Incidentally, her endometrial carcinoma was also positive for CD56 and chromogranin A. Human papillomavirus DNA typing analysis of vulvar tumor was negative. Hence, the vulvar tumor seemed to be a recurrence of the endometrial cancer rather than a primary vulvar neuroendocrine carcinoma. The patient died of the disease within a month.

CONCLUSION

We report a case of vulvar neuroendocrine carcinoma that is independent of Merkel cell polyomavirus and human papillomavirus, thereby suggesting a recurrence of endometrial cancer. Immunohistochemical and virological analyses helped in the differential diagnosis of the neuroendocrine carcinoma.

Sweat-gland carcinoma with neuroendocrine differentiation (SCAND): a clinicopathologic study of 13 cases with genetic analysis

Low-grade neuroendocrine carcinoma of the skin (LGNECS) was proposed in 2017 as a new primary cutaneous neoplasm with neuroendocrine differentiation; however, it is not yet well known due to its rarity. Herein, we perform a detailed clinicopathologic analysis of 13 cases as well as panel DNA sequencing in three cases. The study included 12 males and 1 female with a median age of 71 (43-85) years. All lesions occurred on the ventral trunk. The mean tumor size was 2.2 (0.8-11.0) cm. The histopathology resembled that of well-differentiated neuroendocrine tumors (NETs) in other organs, but intraepidermal pagetoid spreading was seen in 8 (61.5%) cases and stromal mucin deposits in 4 (30.8%). Immunoreactivity for CK7, CK19, EMA, BerEP4, CEA, chromogranin A, synaptophysin, INSM1, GCDFP15, GATA3, ER, and bcl-2 were present in varying degrees in all tested cases. PTEN c.165-1G>A splice site mutation was detected by panel sequencing in one case, and GATA3 P409fs*99 and SETD2 R1708fs*4 in another case. Lymph node metastasis was seen significantly in cases with tumor size >2.0 cm [8/8 (100%) vs. 1/5 (20%)]. All three cases with size >3.0 cm were in unresectable advanced-stage [3/3 (100%) vs. 1/10 (10%)], and two of the three patients succumbed to the disease. The two cases of death revealed mild nuclear atypia (mitosis: 1/10 HPFs) and moderate nuclear atypia (2/10 HPFs). Thus, tumor size would be a better prognostic factor than nuclear atypia, mitotic count, and Ki67 index, unlike in NETs. These clinicopathologic and immunohistochemical features would represent the characteristics as skin adnexal tumors with apocrine/eccrine differentiation rather than NETs; therefore, we rename it as sweat-gland carcinoma with neuroendocrine differentiation (SCAND).

Emerging Therapeutic Concepts and Latest Diagnostic Advancements Regarding Neuroendocrine Tumors of the Gynecologic Tract

Neuroendocrine neoplasms (NENs) are particularly rare in all sites of the gynecological tract and include a variety of neoplasms with variable prognosis, dependent on histologic subtype and site of origin. Following the expert consensus proposal of the International Agency for Research on Cancer (IARC), the approach in the latest World Health Organization (WHO) Classification System of the Female Genital Tumours is to use the same terminology for NENs at all body sites. The main concept of this novel classification framework is to align it to all other body sites and make a clear distinction between well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The previous WHO Classification System of the Female Genital Tumours featured more or less the same principle, but used the terms ‘low-grade neuroendocrine tumor’ and ‘high-grade neuroendocrine carcinoma’. Regardless of the terminology used, each of these two main categories include two distinct morphological subtypes: NETs are represented by typical and atypical carcinoid and NEC are represented by small cell neuroendocrine carcinoma (SCNEC) and large cell neuroendocrine carcinoma (LCNEC). High-grade NECs, especially small cell neuroendocrine carcinoma tends to be more frequent in the uterine cervix, followed by the endometrium, while low-grade NETs usually occur in the ovary. NENs of the vulva, vagina and fallopian tube are exceptionally rare, with scattered case reports in the scientific literature.

Nonsquamous Lesions of the Vulvar Skin and Subcutaneous Tissue: A Review (Part 1)

OBJECTIVES

This article aimed to review "nonsquamous lesions of the vulvar skin and subcutaneous tissue" clinically and pathologically, based on the fifth edition of the World Health Organization tumor classification.

MATERIALS AND METHODS

A database search of PubMed and Google Scholar was performed between 1970 and 2021, using the search terms "vulva," "lower genital tract," and "nonsquamous lesions." The search was limited to "humans," "gynecopathology," and "dermatopathology." Full article texts were reviewed. Reference lists were screened for additional articles. We excluded articles written in the non-English language and abstracts.

RESULTS

A list of 600 articles was identified. Another screening identified 68 articles for clinicopathological features of nonsquamous lesions of the vulvar skin and subcutaneous tissue. In the first part of this review, we cover 5 major groups of nonsquamous lesions of the vulvar skin and subcutaneous tissue including (1) glandular tumors and cysts, (2) adenocarcinomas of other types, (3) germ cell tumors of the vulva, (4) neuroendocrine neoplasia, and (5) hematolymphoid hyperplasia and neoplasia. The rest of the major topics including mesenchymal tumors of the lower genital tract, melanocytic lesions, and metastasis will be discussed in the second part of this review.

CONCLUSIONS

Clinicopathological features of nonsquamous lesions of the vulvar skin and subcutaneous tissue as categorized by the updated World Health Organization classification are presented.

Undifferentiated and dedifferentiated neoplasms of the female genital tract

Undifferentiated neoplasms in the female gynecologic tract comprise two main groups-undifferentiated carcinoma, most common in the endometrium and ovary, and undifferentiated uterine sarcoma, although tumors with an undifferentiated appearance may occur in all gynecologic organs. Their differential diagnosis is broad and generous sampling, careful morphological evaluation, judicious use of immunohistochemistry, and in many cases, molecular testing is often essential in the diagnostic work-up. As some of these neoplasms fail to respond to conventional chemotherapy regimens and/or radiation therapy, targeted therapy may be valuable in treating these highly aggressive tumors, thus the importance of precise diagnosis. In this review we discuss the clinicopathological features of undifferentiated carcinoma, dedifferentiated carcinoma, and undifferentiated uterine sarcoma, followed by a comprehensive analysis of morphological mimickers. Finally, we briefly review ovarian and lower genital tract tumors with an undifferentiated histological appearance.