Merkel's cell (neuroendocrine) carcinoma of the vulva

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.

The puzzle of gynecologic neuroendocrine carcinomas: State of the art and future directions

Primary gynecologic neuroendocrine carcinomas (gNECs) are a heterogeneous spectrum of rare and highly aggressive neoplasms, accounting for about 2% of all gynecologic malignancies, which mostly resemble the small cell lung carcinoma (SCLC). Due to the lack of standardized treatment guidelines, their management poses a noteworthy clinical challenge. Currently, cumulative data retrieved from the management of SCLC and from retrospective studies supports a multimodality strategy, based on surgery, chemotherapy, and radiotherapy. Nevertheless, the prognosis remains poor and recurrences are extremely frequent. Hence, there is an urgent need for novel treatment options and promising molecular targets. Recently, there has been an increasing interest on the potential role of immune checkpoint inhibitors, especially in the recurrent setting. However, only scant evidence exists and there is still a long road ahead. A solid collaboration between gynecologists and oncologists worldwide is required to improve the treatment of these puzzling tumors.

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

Vulvar high-grade neuroendocrine carcinomas (HGNECs) are rare and primarily thought to represent Merkel cell carcinoma (MCC). We present the clinicopathologic features of 16 such cases, the largest series to date. Patients were most often White, postmenopausal, and symptomatic from a palpable vulvar mass/nodule. Tumors ranged from 0.7 to 6 cm and most commonly involved the labium majus. Majority of the cases were pure HGNECs (15/16) with small cell (SC) morphology (14/16); 2 were large cell neuroendocrine carcinomas, of which 1 was combined with moderately differentiated adenocarcinoma. All tumors expressed synaptophysin. Of the 14 HGNECs with SC morphology, 6 were CK20-positive MCCs with characteristic CAM5.2 and neurofilament (NF) expression. Five of these MCCs were positive for Merkel cell polyoma virus large T-antigen (MCPyVLTAg). In contrast, 6 HGNECs with SC morphology were negative for CK20, NF, and MCPyVLTAg and classified as SCNECs. High-risk human papilloma virus was positive in all SCNECs and negative in all MCCs. One case of HGNEC with SC morphology could not be entirely characterized due to lack of tissue for ancillary testing. Five of 12 (42%) cases had a discrepant diagnosis initially rendered. Most patients (10/15) presented with International Federation of Gynecology and Obstetrics stage III or IV disease. Usual sites of metastasis included inguinal lymph node, liver, bone, and lung. Twelve patients underwent surgery with adjuvant chemotherapy and/or radiation therapy, 1 received adjuvant immunotherapy, and 1 patient received neoadjuvant chemotherapy followed by surgery and adjuvant radiation therapy. Median overall survival was 24 months (range: 7 to 103 mo), and overall 5-year survival was 12% (95% confidence interval: 1% to 39%). In summary, vulvar HGNECs are rare, aggressive neoplasms that can be further subclassified into MCC, SCNEC, and large cell neuroendocrine carcinoma. CK20, CAM5.2, NF, TTF-1, MCPyVLTAg, and high-risk human papilloma virus facilitate the distinction of MCC from SCNEC. Proper identification of vulvar HGNECs is critical for patient management.

Pathology of Neuroendocrine Tumours of the Female Genital Tract

Neuroendocrine tumours are uncommon or rare at all sites in the female genital tract. The 2014 World Health Organisation (WHO) Classification of neuroendocrine tumours of the endometrium, cervix, vagina and vulva has been updated with adoption of the terms low-grade neuroendocrine tumour and high-grade neuroendocrine carcinoma. In the endometrium and cervix, high-grade neoplasms are much more prevalent than low-grade and are more common in the cervix than the corpus. In the ovary, low-grade tumours are more common than high-grade carcinomas and the term carcinoid tumour is still used in WHO 2014. The term ovarian small-cell carcinoma of pulmonary type is included in WHO 2014 for a tumour which in other organs is termed high small-cell neuroendocrine carcinoma. Neuroendocrine tumours at various sites within the female genital tract often occur in association with other neoplasms and more uncommonly in pure form.

Clinical features and treatment of vulvar Merkel cell carcinoma: a systematic review

Background

Merkel cell carcinoma is a rare and aggressive neoplasm originating from mechanoreceptor Merkel cells of the stratum basale of the epidermis. Cases affecting the vulva are exceedingly rare, with the currently available literature primarily in case report form.

Body

Systematic review of the PubMed database returned 17 cases of Merkel cell carcinoma affecting the vulva. Patients presented at a mean age of 59.6 years with a firm, mobile vulvar mass. Symptoms of pain, erythema, pruritus, edema, and ulceration have been reported. Tumor histology is consistent with that of neuroendocrine tumors and typical Merkel cell carcinomas. Neuroendocrine and cytokeratin immunostains are frequently utilized in histopathological workup. Surgical management was the unanimous first-line therapy with adjuvant radiation in most cases. Recurrence occurred in 70.6% of patients at a mean follow-up of 6.3 months. Mortality was at 47.0% at a mean of 7.8 months after initial operation.

Conclusion

Merkel cell carcinoma affecting the vulva is an extremely rare and highly aggressive neoplasm. The present review of published cases serves to comprehensively describe the clinical course and treatment approaches for vulvar Merkel cell carcinoma.

Merkel cell carcinoma of the genitourinary tract

Merkel cell carcinomas are rare cutaneous neoplasms that are known to metastasize to various mucosal sites, including the genitourinary tract. Primary Merkel cell carcinomas of the genitourinary tract are extremely rare and may be mistaken for other more common carcinomas of the genitourinary tract, including urothelial carcinomas and prostatic carcinomas. However, primary Merkel cell carcinoma of the genitourinary tract is a very aggressive tumor with poor prognosis. Accurate diagnosis is crucial for appropriate clinical treatment. The discovery of the Merkel cell polyomavirus as a possible causative agent adds a new dimension in the understanding of the pathogenesis and diagnosis, and possible targeted therapies for this tumor.

Vulvar merkel carcinoma: a case report

This is a new case of Merkel cell carcinoma of the vulva. It is a rare neuroendocrine carcinoma with an aggressive behavior. Because of its rarity in this location, it is not clear whether it behaves differently from the usual neuroendocrine carcinomas of the skin. A case of a 63-year-old patient with vulvar Merkel carcinoma is presented. The clinical presentation, microscopic and immunohistochemical features, and treatment are discussed.

Detection of Merkel cell carcinoma polyomavirus in mucosal Merkel cell carcinoma

A 61-year-old woman presented with solitary lymphadenopathy suspicious for lymphoma. An excisional biopsy of a right inguinal lymph node demonstrated metastatic Merkel cell carcinoma (MCC). No skin lesions were detected, but a primary nasopharyngeal mass was identified. A microscopic examination of the nasopharyngeal tumor and the lymph node metastasis showed a monotonous population of small- to intermediate-sized, round blue cells with vesicular nuclei, finely granular and dusty chromatin, and multiple nucleoli. Immunohistochemistry showed perinuclear dot-like staining for cytokeratins AE1/AE3 and CK20. Microscopic appearance and immunohistochemical stains were consistent with MCC. MCC was recently shown to harbor a novel polyomavirus, Merkel cell polyomavirus (MCPyV), in the majority of cases. In this case, MCPyV was detected in the primary tumor and metastasis using polymerase chain reaction and CM2B4 immunohistochemical stain. This is the first report to demonstrate the presence of MCPyV and CM2B4 in a mucosal MCC and its metastasis.

Metastatic Merkel cell carcinoma in the rectum: report of a case

Merkel cell carcinoma is a rare, aggressive skin malignancy of neuroendocrine origin with predominant occurrence in the elderly males. Approximately 50 percent of patients with Merkel cell carcinoma develop distant metastasis at some point during the disease course; hence, Merkel cell carcinoma always has a poor prognosis. Distant metastasis has never been disclosed in the rectum to the best of our knowledge. We present a 76-year-old male with clinical manifestation of massive hematochezia and final diagnosis of metastatic Merkel cell carcinoma in the rectum. We conclude that radical resection of rectal metastatic Merkel cell carcinoma is important in the management strategy of a patient with recurrence and lymph node metastases.

Merkel cell carcinoma: critical review with guidelines for multidisciplinary management

Merkel cell carcinoma (MCC) is a relatively rare cutaneous malignancy that occurs predominantly in the older white population. The incidence of MCC appears to have tripled during the past 20 years; an increase that is likely to continue because of the growing number of older Americans. The pathogenesis of MCC remains largely unknown. However, ultraviolet radiation and immunosuppression are likely to play a significant pathogenetic role. Many questions currently remain unanswered regarding the biologic behavior and optimal treatment of MCC. Large, prospective, randomized studies are not available and are unlikely to be performed because of the rarity of the disease. The objective of this review was to provide a comprehensive reference for MCC based on a critical evaluation of the current data. The authors investigated the importance of sentinel lymph node biopsy as a staging tool for MCC to assess the status of the regional lymph node basin and to determine the need for additional therapy to the lymph node basin. In an attempt to standardize prospective data collection with the intention to define prognostic indicators, the authors also present histopathologic profiles for primary MCC and sentinel lymph nodes. The controversies regarding the appropriate surgical approach to primary MCC, the use of adjuvant radiation therapy, and the effectiveness of adjuvant chemotherapy were examined critically. Finally, the authors have provided treatment guidelines based on the available evidence and their multidisciplinary experience.

Merkel Cell Carcinomas

Merkel cell carcinoma (MCC) is a rare and extremely aggressive skin cancer that arises from primary neural cells. It presents most commonly in the elderly and immunocompromised patients. Pathologically, MCC should be distinguished from extrapulmonary small cell lung cancer or metastatic small cell lung cancer or a small cell variant of melanoma. The prognosis is based largely on the stage of disease at the time of presentation. Therapeutic options for MCC include wide resection with or without adjuvant radiotherapy or chemotherapy. Novel therapies based on the understanding of the molecular aspects of MCC are currently being explored.

Merkel cell cancer of the skin

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumor of the elderly with rapidly growing skin nodules found predominantly on sun-exposed areas of the body. The vast majority of patients present with localized disease, while up to 30% have regional lymph node metastases. Despite local excision and the incidence of local recurrence, regional lymph node metastases and distant metastases is high and usually occurs within 2 years of primary diagnosis. The optimal treatment for patients with MCC remains unclear. The best outcome is achieved with multidisciplinary management including surgical excision of primary tumor with adequate margins and post-operative radiotherapy (RT) to control local and regional disease. Patients with regional nodal metastases should be treated with lymph node dissection plus RT. Adjuvant chemotherapy (CT) should be considered as part of the initial management. In case of metastatic disease CT based on regimens used for small-cell lung cancer is the standard treatment of care.

Bartholin's gland carcinoma, malignant melanoma and other rare tumours of the vulva

Non-squamous cancers of the vulva encompass an exciting and broad group of tumours, including Bartholin's gland carcinoma, malignant melanoma, Paget's disease, sarcomas and lymphoma. These tumours range from innocuous lesions treatable with simple local excision, such as basal-cell carcinoma, to cancers with very poor prognosis, such as Merkel-cell tumours. All of these tumours are thoroughly reviewed, with emphasis on presenting symptoms, pathological diagnosis and optimal management approaches. The literature supporting these recommendations is reviewed. Of the utmost importance in the management of these tumours is a thorough review of the pathological diagnosis by a specialist pathologist and a gynaecological oncologist. Establishing the correct diagnosis is essential to reaching appropriate treatment decisions. Frequently this will necessitate a second opinion by a referral centre.

Merkel cell (neuroendocrine) carcinoma of the vulva. A case report with immunohistochemical and ultrastructural findings and review of the literature

A new case of primary Merkel cell carcinoma (MCC) of the vulva is reported and the literature reviewed for noting its clinical presentation, microscopic, immunohistochemical and ultrastructural features, as well as for establishing the role of immunohistochemistry in the ultimate diagnosis of this uncommon and aggressive tumor. The lesion occurred in a 79 year old patient. Histologically, the tumor was composed of intradermal small cells with high mitotic index and frequent apoptosis. The immunohistochemical study showed positivity for wide spectrum and low molecular weight cytokeratins, epithelial membrane antigen, neurofilaments, neuron specific enolase and chromogranin A. Electron microscopy revealed intermediate filaments in a typical globular paranuclear arrangement. The coexpression of cytokeratins (including cytokeratin 20) and neurofilaments, both in typical globular paranuclear arrangement, made possible the diagnosis of MCC, differentiating it from other malignant small cell tumors such as neuroendocrine metastatic carcinoma.

Merkel cell carcinoma of the skin

BACKGROUND

Neuroendocrine/Merkel cell carcinoma (MCC) of the skin is an uncommon tumour. Currently, there are only limited data available on the natural history, prognostic factors, and patient management of MCC.

OBJECTIVES

To review our experience and build the largest database from the literature.

METHODS

Twenty-eight cases from the London Regional Cancer Center were combined with 633 cases obtained from the literature searched in English, French, German, and Chinese for the years 1966 to 1998. The database included age, sex, initial disease status at presentation to the clinic, site of primary, any coexisting disease, any previous irradiation, sizes of primary/nodal/distant metastases, management details, and final disease status. A new modified staging system was used: stage Ia (primary disease only, size > 2 cm), stage Ib (primary disease only, size > 2 cm); stage II (regional nodal disease), and stage III (beyond regional nodes and/or distant disease).

RESULTS

Age > 65 years, male sex, size of primary > 2 cm, truncal site, nodal/distant disease at presentation, and duration of disease before presentation (< or =3 months) were poor prognostic factors. Surgery was the initial treatment of choice and it significantly improved overall survival (p =.004).

CONCLUSIONS

We identified poor prognostic factors that may necessitate more aggressive treatment. The suggested staging system, incorporating primary tumour size, accurately predicted outcomes.

Chemotherapy in neuroendocrine/Merkel cell carcinoma of the skin: case series and review of 204 cases

PURPOSE

To study the use of chemotherapy for Merkel cell carcinoma (MCC) of the skin.

PATIENTS AND METHODS

Twenty-five cases of MCC were treated at the London Regional Cancer Center between 1987 and 1997. Thirteen cases treated with chemotherapy were reviewed with 191 cases from the literature.

RESULTS

At presentation, 24 patients had localized skin lesions (stage I) and one had locoregional involvement (stage II). Among the nine cases with recurrent nodal disease, six had chemotherapy as a component of salvage treatment. They were all free of disease at a median of 19 months (range, 12 to 37 months). In contrast, two patients who had salvage radiotherapy alone died of disease. Overall survival (OS) and disease-free survival (DFS) were 59% and 43%, respectively, at two years. Median OS and DFS were 29 months (range, 1 to 133 months) and 9 months (range, 1 to 133 months), respectively. Nodal disease developed in 12 (50%) of 24 patients with stage I disease, and distant metastases developed in six (25%) of 24. Including those from the literature, there were 204 cases treated with chemotherapy. Cyclophosphamide/doxorubicin (or epirubicin)/vincristine combination +/- prednisone was the most commonly used chemotherapy regimen (47 cases), with an overall response rate of 75.7% (35.1% complete, 35. 1% partial, and 5.4% minor responses). Etoposide/cisplatin (or carboplatin) was the next most commonly used regimen (27 cases), with an overall response rate of 60% (36% complete and 24% partial responses). The difference in response rate was not statistically significant (P =.19). Among the 204 cases, there were seven (3.4%) toxic deaths.

CONCLUSION

Chemoradiation for locally recurrent or advanced disease may be an option for patients with a good performance status.

Chemotherapy for patients with locally advanced or metastatic Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a highly malignant skin neoplasm. Regional lymph node and distant metastasis occur in 20-52% of patients. The role of chemotherapy in the treatment of patients with this rare tumor is unclear.

METHODS

An exhaustive analysis of the literature (1980-1995) describing chemotherapy for patients with locally advanced or metastatic MCC was performed. All available published medical records (n = 101 patients) were entered in a database. In addition, data on six additional patients given chemotherapy during this time frame in Lyon, France, were included in the database.

RESULTS

For the 107 patients, the overall objective response rate to first-line chemotherapy was 61% (61 of 101 evaluable patients). The response rate was 57 % (41 of 72) for patients with metastasis and 69% (20 of 29) for patients with locally advanced tumors. No clinical parameter was found to be correlated to response to chemotherapy. A high rate of toxic death during first-line treatment (n = 7.7%) was reported for these patients. The median overall survival from the date of chemotherapy initiation was 9 months for patients with metastasis and 24 months for patients with locally advanced tumors. The projected overall survival at 3 years was 17% for patients with metastasis and 35% for patients with locally advanced tumors. Progression after first-line chemotherapy was associated with significantly worse survival for patients with metastasis. Rates of response to second-line (n = 33) and third-line (n = 10) chemotherapy were 45% and 20%, respectively.

CONCLUSIONS

MCC is chemosensitive but rarely chemocurable in patients with metastasis or locally advanced tumors. A high incidence of toxic death due to chemotherapy is reported in the literature.

Small cell carcinoma arising from the outer urethral orifice: a case report examined by histologic, ultrastructural and immunohistochemical methods

A case of small cell carcinoma arising in the outer urethral orifice is presented. The resected tumor showed a proliferation of small round or fusiform neoplastic cells in the submucosa. Tumor cells were arranged in sheets or a trabecular manner and possessed markedly hyperchromatic nuclei with a high N:C ratio, closely resembling small cell carcinoma of the lung. Characteristically, pagetoid intraepithelial spreading could be identified. However, there was no evidence of in situ transitional cell carcinoma and adeno- or squamous cell carcinoma components anywhere. Ultrastructurally, each tumor cell contained only a few membrane-bound cored granules measuring 60-100 nm, which were compatible with neurosecretory granules, and desmosome-like intercellular attachments, but lacked aggregated microfilaments. By immunohistochemical examination, tumor cells were positive for epithelial markers, such as cytokeratin and epithelial membrane antigen, and neuron specific enolase, but negative for any other neuro-endocrine markers. Extensive systemic examination failed to show the primary site to be other than the outer urethral orifice. These findings indicate that the current tumor is a small cell carcinoma with neuro-endocrine differentiation arising from the outer urethral orifice.

[Merkel cell carcinoma: primary cutaneous neuroendocrine tumor]

Merkel cell carcinoma is a neuroendocrine primitive tumor of the skin. We report a case who develops node and visceral metastasis, and dead. The clinical presentation, diagnosis, histology, immunocytochemistry, treatment and prognosis of this tumor will be discussed.

Merkel cell tumor in a woman with chronic lymphocytic leukemia

We describe a 69-year-old woman with basal cell carcinoma, and chronic lymphocytic leukemia who developed Merkel cell tumor. This latter malignancy first appeared as enlarged lymph nodes in the axilla and elbow regions and responded initially to radiotherapy. Later, the patient developed obstructive jaundice which was due to pancreatic metastases of the Merkel cell tumor, documented by post-mortem examination. To our knowledge, this is the first description of a Merkel cell tumor causing obstructive jaundice, in a patient with chronic lymphocytic leukemia.

Penile Merkel cell carcinoma

Merkel cell carcinoma of the genitalia is very rare and to date has been found only in vulvar mucosa. We describe an aggressive Merkel cell tumor in the frenulum of the penis with lymph node metastases, local recurrence, and eventually widespread dissemination. The primary tumor was associated with discontiguous squamous cell carcinoma in situ. This is the first report of Merkel cell (neuroendocrine) carcinoma in this anatomic site.