Neuroendocrine (Merkel cell) carcinoma of the vulva: a case report and review of the literature

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.

Update on Merkel Cell Carcinoma: Epidemiology, Etiopathogenesis, Clinical Features, Diagnosis, and Staging

Merkel cell carcinoma (MCC) is a rare, highly aggressive tumor, and local or regional disease recurrence is common, as is metastasis. MCC usually develops in sun-exposed skin in patients of advanced age. Its incidence has risen 4-fold in recent decades as the population has aged and immunohistochemical techniques have led to more diagnoses. The pathogenesis of MCC remains unclear but UV radiation, immunosuppression, and the presence of Merkel cell polyomavirus in the tumor genome seem to play key roles. This review seeks to update our understanding of the epidemiology, etiology, pathogenesis, and clinical features of MCC. We also review histologic and immunohistochemical features required for diagnosis. MCC staging is discussed, given its great importance in establishing a prognosis for these patients.

Neuroendocrine tumors of the gynecologic tract: select topics

Tumors of the diffuse neuroendocrine cell system (DNES) may arise in any component of the gynecologic tract, including the vulva, vagina, cervix, endometrium, and ovary. Overall such tumors in the gynecologic tract are rare, constituting only 2% of gynecologic cancers, comprising a spectrum of tumors of variable biologic potential. Due to the rarity of such tumors, pathologists experience may be limited and these may present diagnostic challenges. Currently the nomenclature employed is still that of the pulmonary classification systems, carcinoid, atypical carcinoid, small and large cell neuroendocrine carcinoma that broadly correlates to low/grade 1, intermediate/grade 2, and high grade/grade 3 of the WHO gastroenteropancreatic neuroendocrine tumors classification. Furthermore in keeping with the lung, proliferative rate is assessed based on mitotic index rather than Ki-67 staining. In this review we cover select neuroendocrine tumors of the gynecologic tract.

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.

Small cell carcinoma of vulva: curative multimodal treatment in face of resistance to initial standard chemotherapy

BACKGROUND AND PURPOSE

Extrapulmonary small cell carcinoma (EPSCC) is a rare disease, which has a slightly better prognosis than small cell lung cancer, but still dismal. Gynecologic small cell malignancies tend to show a better survival than similar histologies of other regions. However, of five reported cases of vulvar manifestation only one patient was disease-free at the time of publication with limited follow-up.

CASE REPORT

The authors describe a case of locally advanced small cell vulva carcinoma infiltrating the anal sphincter and urethra with spread to inguinal lymph nodes treated by radiochemotherapy and regional hyperthermia. After three cycles of carboplatin/ etoposide, computed tomography and magnetic resonance imaging indicated only little regressive transformations but overall stable disease. Surgical options were excluded. Therefore, curative radiotherapy to a total dose of > 65 Gy to macroscopic tumor, chemotherapy with cisplatin weekly, and regional hyperthermia were performed. Acute severe toxicity was limited to skin reactions. Despite the disadvantageous situation with inguinal lymph node metastases and chemoresistance, the multimodal therapy yielded a 5-year disease-free survival.

CONCLUSION

Thus, the trimodal regimen of radiochemotherapy plus regional hyperthermia offered a curative chance in spite of resistance to the standard chemotherapy for irresectable, locally advanced small cell carcinoma of the vulva. Therefore, this approach merits further evaluation for limited disease of EPSCC.

[Small-cell carcinoma of the vulva]

Small-cell carcinoma is a rare and aggressive malignancy; this tumor is lethal due to the propensity to metastasize early in the course of the disease. It occurs most frequently in the lung. Small-cell cancer also rarely may occur in the female genital tract, usually in the cervix. This article concerns the fifth reported case of small-cell carcinoma of the vulva in a 34-year-old women who had developed a vulvar mass3 months earlier. The physical examination revealed bilateral inguinal lymph nodes. The mass was excised and the histological finding was a small-cell carcinoma. Postoperative search for metastasis included computed tomography scan of the abdomen, pelvis, chest and brain that showed right iliac lymph nodes. The osteo medullar biopsy was positive. The patient was treated with 6 cycles of chemotherapy including cisplatinum (80mg/m2 d1) and etoposide (100mg/m2 d1 d2 d3). Adjuvant radiotherapy (50Gy) was administered but the disease progressed and the patient died after 7 months. Small-cell carcinoma of the vulva is a very rare tumor. Similarly to small-cell cancers arising in other sites, it appears that regional therapy is not a sufficient treatment for this tumor. Chemotherapy should be used to improve outcome.

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.

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. Diagnosis and treatment

BACKGROUND

Merkel cell carcinoma is an uncommon malignancy of the skin that often portends a poor prognosis. Since its first description by Toker in 1972, a plethora of case reports and articles regarding the etiopathogenesis and treatment have been published spanning multiple medical and surgical disciplines. Much confusion still exists regarding the diagnosis and treatment of this ominous tumor.

OBJECT

Through extensive review of the medical, surgical, and pathological literature, to collate the observations of multiple investigators and summarize these findings.

METHODS

Articles from journals of multiple subspecialties were carefully reviewed with particular emphasis placed on epidemiology, prognosis, histology, immunohistochemistry, electron microscopy, tumor origin, treatment, and work-up of Merkel cell carcinoma.

RESULTS

Merkel cell carcinoma is an aggressive malignant neoplasm. Local recurrence develops in 26-44% of patients despite therapy. Up to three-fourths of patients eventually develop regional nodal metastases with distant metastases occurring in one-third of all patients. Reported overall 5-year survival rates range from 30% to 64%.

CONCLUSION

Treatment recommendations unfortunately are based more on anecdotal than scientific data because of the rarity of the tumor and its recognized high risk. Most authors recommend wide local excision of the primary lesion and regional lymph node resection if lymph nodes are palpable followed by x-irradiation of both the postsurgical bed and lymph node basin. The role of elective lymph node resection in the absence of clinically positive nodes remains controversial.

Merkel's cell (neuroendocrine) carcinoma of the vulva

BACKGROUND

Merkel's cell carcinoma rarely arises in the vulva. It is unclear whether those cases arising in the vulva behave differently from the usual Merkel's cell carcinomas.

METHODS

A Merkel's cell carcinoma of the vulva was studied by light microscopy, immunohistochemistry, and electron microscopy. The clinical data of this case and of other reported cases are summarized and compared with those of Merkel's cell carcinoma in general.

RESULTS

This tumor showed the characteristic trabecular pattern of Merkel's cell carcinoma. The tumor cells were immunoreactive to low-molecular-weight cytokeratin and neuron-specific enolase. This patient was treated initially with local excision. She died 17 months later with progressive metastatic disease unresponsive to chemotherapy. This case study and the review of six other cases indicate that Merkel's cell carcinoma of the vulva is universally metastatic, both to the regional lymph nodes and distant sites, and that it invariably follows a rapidly fatal course.

CONCLUSION

Merkel's cell carcinoma of the vulva appears to have a biologic behavior more aggressive than that of Merkel's cell carcinoma in general. An initial modality combining chemotherapy, with or without irradiation, with aggressive surgery should be tried in future cases.

Small cell (neuroendocrine) carcinoma of the vagina

We report a case of vaginal small cell (neuroendocrine) carcinoma. Immunostaining for neuron-specific enolase, PGP 9.5, chromogranin, synaptophysin, Leu 7 and cytokeratin was positive. Neurosecretory granules were found by electronmicroscopy. There was local recurrence and regional lymph node metastases. The patient survived for 10 months following local surgical therapy only.

Stage I small cell carcinoma of the vulva treated with vulvectomy, lymphadenectomy, and adjuvant chemotherapy

Neuroendocrine small cell carcinoma is a lethal, but rare, tumor that arises most frequently in the lung. Small cell cancer also rarely may occur in the female genital tract, usually in the cervix. This article concerns the fourth reported case of neuroendocrine small cell carcinoma of the vulva. Previously, small cell carcinoma of the vulva has been treated with regional therapy including surgery and radiation. Survival has been poor, however, due to the propensity of these tumors to metastasize early in the course of the disease. Recently, the median survival of patients with small cell carcinoma of the lung has been improved with the use of chemotherapy. The authors review the literature on the treatment of small cell carcinoma of the vulva and report on a patient who was treated successfully with vulvectomy and inguinal lymphadenectomy followed by adjuvant chemotherapy.

The essential role of radiation therapy in securing locoregional control of Merkel cell carcinoma

Between 1966 and 1987, 54 patients with non-disseminated Merkel cell carcinoma (MCC) were treated with curative intent at the University of Texas M. D. Anderson Cancer Center. The primary tumor site was in the head and neck in 38 patients. The majority of the patients (57%) were referred with locoregionally recurrent disease. For the whole group, survival was 30% after 5 years. Patients who presented with nodal involvement had a median survival of 13 months compared with 40 months for node-negative patients (p less than .04). Only 4/37 patients treated initially by surgery alone were locoregionally controlled, with a median time to recurrence of 4.9 months. Salvage with radiation therapy was attempted in 18 patients (after additional surgery in 14), but was successful in only four. The predominant failure pattern in this subgroup was distant metastases, occurring as a component of initial recurrence in 12/18 patients. Prior to 1982, the philosophy of initial therapy was to give postoperative irradiation only to patients with large primaries or nodal involvement. Subsequently, postoperative radiotherapy has been recommended routinely, and all five patients treated with this approach remain disease-free. In total, 31 patients (including 10 patients with gross disease) were irradiated at M. D. Anderson; only one developed an in-field locoregional recurrence as an initial site of failure. However, three marginal recurrences occurred. The median dose to the primary tumor, first echelon nodes, and supraclavicular nodes was 60, 51, and 50 Gy, respectively. Our current recommendation for initial treatment is excision of the primary tumor followed by irradiation with generous fields to include the primary tumor site and draining regional lymphatics to doses of 46-50 Gy in 2 Gy fractions. For gross unresected disease, 56-60 Gy is recommended. The role of adjuvant systemic therapy remains to be defined.

Merkel cell carcinoma of the vulva: a case report

The clinical and pathologic findings of Merkel cell carcinoma of the vulva were reported. The light microscopic findings of sheets of small, uniform cells were consistent with a diagnosis of neuroendocrine tumor. The electron microscopic characteristics revealed membrane-bound secretory granules, confirmed the diagnosis of Merkel cell carcinoma. Regional lymphnode metastases were present at the time of initial surgery and the adjunctive radiotherapy was also given. This case was unusual because Merkel cell carcinoma was usually found on the face, extremities and buttocks.

[Clinical aspects and therapy of Merkel cell tumor--report of 4 personal cases and review of the literature]

Four cases of Merkel cell tumor located in the face or on the trunk are presented. In a literature review 339 cases were found and analysed. The Merkel cell tumor is a neuroendocrine tumor of the skin derived from the Merkel cells. It is located most often in the face and neck area. Typically, it is an exophytic node, has a red-blue color and measures 25 mm in diameter on the average. Since it is metastasizing it is a malignant tumor. Regional node metastases were found in 27%, local recurrences occur in 51%, and distant metastases were seen in 32% of the cases. The best therapy is excision with wide margins as is the rule for a malignant skin tumor. While the tumor reacts to radiotherapy, chemotherapy seems to be of no help.