Primary neuroendocrine (merkel cell) carcinoma of the anterior skull base

The Evaluation and Treatment of Merkel Cell Carcinoma and Brain Metastasis: A Case Report and Review of the Literature

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumor associated with high mortality if metastases are identified. Currently, there is no standardized nor curative treatment for neurometastatic MCC. In this study, we have reviewed the more recent cases and the use of immunotherapy in a population. In this case report and review, we present a case of MCC with brain metastasis currently undergoing treatment with immunotherapy (pembrolizumab) resulting in an initial complete response with a progression-free survival time of five months. We also review the past reported literature and the 11 newly presented cases on their clinical presentation of neurometastatic MCC, immunohistochemical markers, and treatment outcomes. In summary, immunotherapy initially showed a promising response with the complete elimination of MCC brain metastasis. The early aggressive treatment of pembrolizumab with stereotactic radiosurgery should be considered as this treatment plan has shown improved therapeutic effects compared to the standard chemoradiation therapy. Further investigations are needed to determine the efficacy and response of immunotherapy use for neurometastatic MCC.

Unusual skull base metastasis from neuroendocrine tumor: a case report

Background

With increasing treatment options available, neuroendocrine tumor has become a chronic disease and may present later on with atypical manifestation of disease spread once resistant to treatment.

Case presentation

A 74-year-old white British woman undergoing treatment for metastatic well-differentiated neuroendocrine tumor for the past 9 years presented with a brief history of mild frontal headache, and progressive left ptosis and ocular palsy. She had no visual loss, and had neither speech nor motor deficit. At the outset, it was crucial to exclude acute or missed stroke. An urgent magnetic resonance imaging of her head revealed an unusual skull base metastasis extending into the cavernous sinus, with no peritumoral edema. Following discussion at a specialist neuro-oncology meeting and a neuroendocrine tumor multidisciplinary team meeting, she proceeded to have conventional fractionated radiotherapy followed by subsequent palliative chemotherapy.

Conclusions

Intracranial metastasis is rare in patients with neuroendocrine tumor, particularly in those with well-differentiated histology; skull base metastasis is even more uncommon. Management of intracranial metastasis from a rare tumor should always be discussed in a specialist multidisciplinary meeting. Surgery or radiotherapy, including stereotactic radiosurgery, should be considered in skull base metastases. Hormonal abnormalities may occur following radiotherapy to skull base metastases and should be monitored closely in the first few months post treatment.

Merkel Cell Carcinoma with Distant Metastasis to the Clivus Causing Symptoms Mimicking Tolosa-Hunt Syndrome: A Case Report and Literature Review

Merkel cell carcinoma (MCC) is an uncommon but highly malignant neuroendocrine tumor of the skin. MCC can metastasize, but involvement of the central nervous system is rare. Here, we report a case of rapidly progressing metastatic MCC to the clivus and bilateral cavernous sinus in an immunocompromised patient. This case is unique in that it is the first case report showing MCC metastasis to the clivus from a distant site. It also demonstrates that a MCC metastasis can masquerade with symptoms of Tolosa–Hunt syndrome. A literature review on MCC with CNS metastasis is presented.

[Primary cutaneous neuroendocrine carcinoma: report of a new case and literature review]

Le carcinome neuro- endocrine cutané primitif (CNEC) est une tumeur cutanée rare et agressive du sujet âgé, favorisée par le soleil et l'immunodépression. Elle est caractérisée par une évolution agressive avec un fort taux de récidive, une évolution ganglionnaire régionale et un risque de métastases à distance. Nous rapportons un cas de cette tumeur chez un patient âgé de 67 ans sous forme d'un placard nodulaire hémorragique mesurant 16 /14 cm. Le patient a bénéficié d'une exérèse chirurgicale large avec couverture de la perte de substance par un lambeau musculo-cutané du muscle grand dorsal, un curage ganglionnaire axillaire et une radiothérapie adjuvante. Après un recul de 2 ans et 2 mois, le patient est toujours vivant sans métastase ni récidive. La littérature étant pauvre, la prise en charge diagnostique et thérapeutique est controversée et donc hétérogène. Globalement le pronostic est mauvais, et certains paramètres corrélés au pronostic sont précisés.

Intracranial spread of Merkel cell carcinoma to the cerebellopontine angle

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, highly malignant, and aggressive dermal neuroendocrine neoplasm that rarely metastasizes to the central nervous system.

OBJECTIVE

To review the current literature regarding treatment of neurometastatic MCC.

METHODS

A case of a 78-year-old male with intracranial extra-axial metastatic MCC involving the left cerebellopontine angle is presented.

RESULTS

A retrosigmoid craniectomy was performed with complete resection of the metastatic focus. Adjuvant treatment included whole-brain radiation therapy followed by etoposide and carboplatin chemotherapy. Seven months postoperatively, the patient was free of metastatic disease.

CONCLUSION

Surgical resection should be performed when feasible to prevent local recurrence. This may be followed by early adjuvant fractionated whole-brain radiotherapy and systemic chemotherapy; however, no clinical trials have been performed to demonstrate a survival benefit.

Clinical emergence of neurometastatic merkel cell carcinoma: a surgical case series and literature review

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine neoplasm of possible viral origin and is known for its aggressive behavior. The incidence of MCC has increased in the last 15 years. Merkel cell carcinoma has the potential to metastasize, but rarely involves the central nervous system. Herein, we report three consecutive surgical cases of MCC presenting at a single institution within 1 year. We used intracavitary BCNU wafers (Gliadel^®) in two cases. Pathological features, including CK20 positivity, consistent with MCC, were present in all cases. We found 33 published cases of MCC with CNS involvement. We suggest that the incidence of neurometastatic MCC may be increasing, parallel to the increasing incidence of primary MCC. We propose a role for intracavitary BCNU wafers in the treatment of intra-axial neurometastatic MCC.