Merkel cell carcinoma of the inguinal lymph node with an unknown primary site

Merkel cell carcinoma of unknown primary: Clinical presentation and outcomes

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy that usually occurs in the head/neck or extremities. However, there are reports of MCC developing in the lymph nodes or parotid gland without evidence of a primary cutaneous lesion.

METHODS

We reviewed 415 patients with biopsy-proven MCC. Patients with MCC of unknown primary (n = 37, 9%, MCCUP) made up the study cohort. The primary endpoints of the study were rate of recurrence, disease-free survival, and overall survival.

RESULTS

Patients with MCCUP presented with tumors in lymph nodes (n = 34) or parotid gland (n = 3). Nodal disease was most commonly detected in the inguinal/external iliac (n = 15) or axillary (n = 14) regions. The mean age at diagnosis was 70 years and 24% were female. Patients presented with distant metastases in 24.3% of cases. Patients with stage IIIA disease treated with regional lymph node dissection (RLND) had a lower risk of disease recurrence (hazard ratio 0.26, p = 0.046). Recurrence-free survival was 59.3% at 5 years. Disease-specific survival was 63.3% at 5 years.

CONCLUSION

Patients with MCCUP have a high risk of recurrence and mortality. The optimal treatment for MCCUP has yet to be elucidated, although therapeutic RLND appears beneficial for these patients.

Extrapulmonary small cell carcinoma of lymph node: Pooled analysis of all reported cases

AIM

To study clinical outcomes and management of lymph nodes extrapulmonary small cell carcinoma (LNEPSCC).

METHODS

Herein, we perform a systematic search of published literature in the PubMed and EMBASE databases for studies describing LNEPSCC. For uniformity of reporting, LNEPSCC was staged as limited if it involved either single lymph node station or if surgery with curative intent had been undertaken. The disease was staged extensive if it involved two or more lymph node regions.

RESULTS

The systematic literature review yielded eight descriptions (n = 14) involving cervical, submandibular and inguinal lymph nodes. Eleven (64.7%) patients had limited disease (LD) and six (35.3%) had extensive disease (ED) at presentation. Chemotherapy (n = 6, 35.3%) or surgery (n = 4, 23.5%) were the most common form of treatment given to these patients. Complete response was achieved in 12 (70.6%) of the patients. Median (interquartile range) progression free survival and overall survival was 15 (7-42) mo and 22 (12.75-42) mo respectively. Of the three illustrative cases, two patients each had ED at presentation and achieved complete remission with platinum based combination chemotherapy.

CONCLUSION

LNEPSCC is a rare disease with less than 15 reported cases in world literature. Surgical resection with curative intent is feasible in those with LD while platinum based combination chemoradiation is associated with favorable outcomes in patients with ED. Prognosis of LNEPSCC is better than that of small cell lung cancer in general.

Primary retroperitoneal Merkel cell carcinoma: Case report and literature review

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma that affects elderly patients and typically arises in sun-exposed skin. The disease is very rare and only few cases present with no apparent skin lesion. In the retroperitoneum there are only two cases reported in the literature.

CASE PRESENTATION

We report a case of a 54-year-old Mexican male with MCC, which presented as a large retroperitoneal mass. Pathological and immunohistochemical analysis of the transabdominal CT-guided biopsy specimen revealed a MCC. The patient underwent preoperative chemotherapy followed by a laparotomy and the mass was successfully excised.

DISCUSSION

There are two possible explanations for what occurred in our patient. The most plausible theory is the retroperitoneal mass could be a massively enlarged lymph node where precursor cells became neoplastic. This would be consistent with a presumptive diagnosis of primary nodal disease. Moreover, metastasis to the retroperitoneal lymph nodes has been reported as relatively common when compared to other sites such as liver, bone, brain and skin. The less probable theory is the non-described "regression" phenomena of a cutaneous MCC, but we are not found a primary skin lesion.

CONCLUSION

Preoperative chemotherapy and excision of the primary tumor is the surgical treatment of choice for retroperitoneal MCC. We propose that further studies are needed to elucidate the true efficacy of chemotherapy in conventional and unconventional patients with MCC.

Merkel Cell Carcinoma of the Axilla and Adrenal Gland: A Case Report with Imaging and Pathologic Findings

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine carcinoma of the skin. MCC is characterized by a high incidence of locoregional recurrence, and distant metastasis, and often requires short-term follow-up after treatment. In this present paper, we describe a rare case of MCC, which presented as a palpable axillary mass and an incidental adrenal mass, and report on the ultrasonography, computed tomography, and (18)F-fluorodeoxyglucose-positron emission tomography findings. The patient underwent surgery and adjuvant radiation therapy. Seven months after the initial diagnosis, distant metastasis was detected during a follow-up examination.

Merkel cell carcinoma of lymph node with unknown primary has a significantly lower association with Merkel cell polyomavirus than its cutaneous counterpart

Rare cases of Merkel cell carcinoma have been encountered in lymph nodes with unknown extranodal primary, which exhibit similar morphologic and immunophenotypic features to those in primary cutaneous Merkel cell carcinomas. However, it is uncertain whether the nodal Merkel cell carcinoma is a primary tumor of the lymph node or represents a metastasis from an occult or regressed extranodal lesion. To establish an accurate diagnosis of the nodal Merkel cell carcinoma can be challenging because of significant morphologic mimics, including lymphoblastic lymphoma and metastatic small cell carcinoma. Moreover, there is no consensus for a diagnostic term, and many different terms have been used, which can be confusing and may not fully reflect the nature of nodal Merkel cell carcinoma. In this study, we investigated the detailed clinicopathologic features of 22 nodal Merkel cell carcinomas, with comparison to 763 primary cutaneous cases retrieved from the literature. Overall, the nodal and cutaneous Merkel cell carcinomas shared similar clinical presentations, morphologic spectrum, and immunophenotype; both were mostly seen in elderly male with a typical neuroendocrine morphology. Most of cases expressed CK20, synaptophysin, and chromogranin A; and PAX5 and TdT were also positive in majority of cases. However, nodal Merkel cell carcinomas had a significantly lower association with Merkel cell polyomavirus than cutaneous cases (31% vs 76%, P=0.001). Therefore, these two entities may arise from overlapping but not identical biological pathways. We also recommend the use of the diagnostic term 'Merkel cell carcinoma of lymph node' to replace many other names used.

Merkel cell carcinoma of the retroperitoneum with no identifiable primary site

Merkel cell carcinoma (MCC) is an extremely rare primary neuroendocrine neoplasm of the skin that shows aggressive behavior and a poor prognosis. We report a case of a 67-year-old male with a Merkel cell carcinoma which initially presented itself as a large retroperitoneal mass. Pathological and immunohistochemical analysis revealed tissue consistent with neuroendocrine carcinoma. Despite complete medical workup, no other primary MCC could be detected. While being an atypical presentation, the tumor mass showed an excellent response to the combination of chemotherapy followed by radiotherapy.

Imaging in patients with merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor of the skin with a mortality rate of approximately 25% (Peloschek et al., 2010). Accurate assessment of nodal involvement in patients with MCC predicts significantly overall outcome (Smith et al., 2012 and Ortin-Perez et al., 2007). Due to the rarity of this highly aggressive disease, only a few imaging reports on MCC were published, and subsequently still to date no accepted imaging algorithm for MCC is available. For primary staging of MCC, general recommendations have included ultrasonography, chest X-ray CT, and MRI, but recent articles show that the use of sentinel node and FDG-PET/PET-CT is gaining more and more importance.

Unknown primary Merkel cell carcinoma: 23 new cases and a review

BACKGROUND

Knowledge is limited regarding unknown primary Merkel cell carcinoma (UPMCC).

OBJECTIVE

We sought to document the characteristics and behavior of UPMCC, and determine the most appropriate treatment.

METHODS

A multicenter, retrospective, consecutive study reviewing patients given a diagnosis of UPMCC between 1981 and 2008 was completed. In addition, a literature review of cases of UPMCC was performed.

RESULTS

In all, 23 patients with UPMCC are described and 34 cases from previous reports are compiled. Among the 23 new cases of UPMCC, the average age at diagnosis was 66.0 years; the majority of patients were male (87%) and Caucasian (100% of those reported). One patient was immunosuppressed, and 39% had a history of other cancer. After the initial biopsy, 16 patients had further evaluation of the involved lymph node basin. Half of these had additional positive nodes (8 of 16). The majority of patients had lymph node basin involvement only (78%), whereas 22% had lymph node basin and distant metastasis. The most common lymph node basin involved was inguinal. The median size of the involved lymph node at diagnosis was 5.0 cm. At 2 years, the overall survival of stage IIIB UPMCC was significantly improved versus stage IIIB known primary Merkel cell carcinoma (MCC): 76.9% to 36.4%.

LIMITATIONS

Limited number of cases and retrospective review are limitations.

CONCLUSION

Our data demonstrate improved overall survival in patients with stage IIIB UPMCC versus those with stage IIIB known primary MCC. Because of the unpredictable natural history of UPMCC, we recommend individualization of care based on the details of each patient's clinical presentation.

Merkel cell carcinoma in a patient with noninvasive vulvar Paget's disease

We present the first case of inguinal Merkel cell carcinoma of unknown primary origin in a patient with vulvar Paget's disease. Correlation with immune suppression of both entities warrants further investigation. Additionally, this case highlights the value of ultrasound scanning in the detection of inguinal metastasis.