Melanoma patients with unknown primary site or nodal recurrence after initial diagnosis have a favourable survival compared to those with synchronous lymph node metastasis and primary tumour

A patient with rapidly growing axillary masses

ABSTRACT

About 85,000 melanomas are diagnosed every year in the United States, but only about 3.2% are diagnosed without a primary site. This article describes a patient who presented with two rapidly growing axillary masses and was found to have metastatic melanoma of the lymph nodes with no known primary site. Melanoma of unknown primary (MUP) site is staged either III or IV level. Management is determined in the same manner as stage-matched melanoma of known primary site.

Neoadjuvant ipilimumab plus nivolumab in synchronous clinical stage III melanoma

BACKGROUND

Patients with synchronous clinical stage III melanoma can present with primary melanoma lesions, locally recurrent melanoma or in-transit metastases. Neoadjuvant ipilimumab plus nivolumab induces high pathologic response rates and an impressive relapse-free survival in patients with nodal macroscopic stage III melanoma. Whether primary site melanoma and in-transit metastases respond similarly to lymph node metastases with neoadjuvant immunotherapy is largely unknown. Such data would clarify whether surgical excision of these melanoma lesions should be performed before neoadjuvant therapy or whether it could be deferred and performed in conjunction with lymphadenectomy following neoadjuvant immunotherapy.

PATIENTS

Patients with synchronous clinical stage III melanoma were identified from the OpACIN, OpACIN-neo and PRADO neoadjuvant trials, where all patients were treated with ipilimumab plus nivolumab. An additional case treated outside those clinical trials was included.

RESULTS

Seven patients were identified; six patients had a concordant response in primary site melanoma lesions or in-transit metastasis and the lymph node metastases. One patient had concordant progression in both the primary and nodal tumour lesions and developed stage IV disease during neoadjuvant treatment, and thus, no resection was performed.

CONCLUSION

Pathologic response following neoadjuvant ipilimumab plus nivolumab in primary site melanoma lesions or in-transit metastasis is concordant with a response in the lymph node metastases, indicating that there may be no need to perform upfront surgery to these melanoma lesions prior to neoadjuvant treatment.

Clinicopathological Features, Staging, and Current Approaches to Treatment in High-Risk Resectable Melanoma

The incidence of melanoma in the United States has been increasing over the past several decades. Prognosis largely depends on disease stage, with 5-year melanoma-specific survival ranging from as high as 99% in patients with stage I disease to less than 10% for some patients with stage IV (distant metastatic) disease. Fortunately, in the last 5-10 years, there have been remarkable treatment advances for patients with high-risk resectable melanoma, including approval of targeted and immune checkpoint blockade therapies. In addition, results of recent clinical trials have confirmed the importance of sentinel lymph node biopsy and continue to refine the approach to regional lymph node basin management. Lastly, the melanoma staging system was revised in the eighth edition AJCC Cancer Staging Manual, which was implemented on January 1, 2018. Here we discuss these changes and the clinicopathological features that confer high risk for locoregional and distant disease relapse and poor survival. Implications regarding the management of melanoma in the metastatic and adjuvant settings are discussed, as are future directions for neoadjuvant therapies.

Patients with melanoma of unknown primary show better outcome under immune checkpoint inhibitor therapy than patients with known primary: preliminary results

Background: Melanoma of unknown primary (MUP) is an uncommon clinical subtype of melanoma of known primary (MKP). Objectives: We aimed to compare treatment outcomes of MUP and MKP patients who had undergone therapy with immune checkpoint inhibitors (ICPI). Methods: We studied 41 metastatic melanoma patients (32 with MKP and 9 with MUP) with an indication for ICPI. Results: Clinical characteristics such as age, gender, stage of disease, etc., did not significantly differ (P < .05) between MUP and MKP patients. 20/32 (62.5%) melanoma-specific deaths (MSD) were observed in the MKP group, whereas 2/9 (22.2%) were detected in the MUP group (P = .035). On logistic regression, the MUP status proved to be an independent predictor for a more favorable outcome under immunotherapy when compared to MKP (P = .030). Conclusion: Our preliminary results indicate that MUP patients show better clinical outcome under ICPI when compared to MKP.

Regression and Sentinel Lymph Node Status in Melanoma Progression

BACKGROUND The purpose of this study was to assess the role of regression and other clinical and histological features for the prognosis and the progression of cutaneous melanoma. MATERIAL AND METHODS Between 2005 and 2016, 403 patients with melanoma were treated and followed at our Department of Dermatology. Of the 403 patients, 173 patients had cutaneous melanoma and underwent sentinel lymph node (SLN) biopsy and thus were included in this study. RESULTS Histological regression was found in 37 cases of melanoma (21.3%). It was significantly associated with marked and moderate tumor-infiltrating lymphocyte (TIL) and with negative SLN. Progression of the disease occurred in 42 patients (24.2%). On multivariate analysis, we found that a positive lymph node and a Breslow index higher than 2 mm were independent variables associated with disease free survival (DFS). These variables together with a mild TIL were significantly correlated with overall survival (OS). The presence of regression was not associated with DFS or OS. CONCLUSIONS We could not demonstrate an association between regression and the outcome of patients with cutaneous melanoma. Tumor thickness greater than 2 mm and a positive SLN were associated with recurrence. Survival was influenced by a Breslow thickness >2 mm, the presence of a mild TIL and a positive SLN status.

Metastatic Melanoma of a MetatarsalA Case Report

A 53-year-old woman presented with painful swelling of the right forefoot presenting clinically as a metatarsal stress fracture. Radiographs showed destructive changes, and diagnostic imaging revealed an aggressive neoplasm. The lesion was biopsied, and the pathologic diagnosis was metastatic melanoma. A thorough physical examination and advanced imaging did not reveal a primary tumor. Ray resection was performed with en bloc resection of the neoplasm. The patient continues to receive long-term immune stimulation chemotherapy 34 months after the ray resection.

Metastases of Melanoma to Head and Neck Mucosa: A Report of Short Series

Objectives

Metastasis of melanoma to the head and neck mucosa is a very unusual condition. The aim of this study was to report four cases of patients with metastatic melanoma in the head and neck mucosa treated at a single institution.

Methods

Clinical data were obtained from the medical records. All cases were histologically reviewed to confirm the diagnosis, and immunohistochemical reactions were performed in the cases submitted to biopsy.

Results

All patients were males and the mean age was 40.5 years old. The sites of the metastatic tumors were gingival mucosa, floor of the mouth, oropharynx, and larynx. Two tumors appeared as submucosal nodules with normal color; one lesion was a blackish nodular lesion, and one was shown to be an ulcerated lesion. The size of tumors ranged from 2.0 to 4.0 cm. All patients had developed systemic disease at time of diagnosis of metastatic tumor in the head and neck mucosa. Survival rates ranged from 2 to 19 months after the diagnosis of the metastatic mucosal melanoma in the head and neck region.

Conclusion

Although rare, patients with melanoma must be closely and regularly followed up, with careful routine examination of head and neck, because metastatic tumors in this region seem to be part of a lethal widespread metastatic disease.

Utility of sentinel lymph node biopsy for solitary dermal melanomas

BACKGROUND AND OBJECTIVES

Solitary dermal melanoma (SDM) is melanoma confined to subcutaneous and/or dermal layers in the absence of a known primary cutaneous lesion. We hypothesized that sentinel node biopsy is an effective staging strategy for this rare disease.

METHODS

A Markov decision model was constructed to represent two management strategies for SDM: wide local excision followed by observation, and wide local excision followed by sentinel node biopsy. Utilities, likelihood of positive sentinel node biopsy, and cancer progression rates during a five year time horizon were assigned based on institutional data and a review of existing literature. Estimated costs were derived using Medicare reimbursements.

RESULTS

Excision followed by sentinel node biopsy provides greater utility, yielding 3.85 discounted quality-adjusted life years (dQALY) compared to 3.66 for excision alone. The incremental cost-effectiveness ratio for sentinel node biopsy is $19,102 per dQALY. Sensitivity analyzes demonstrated that observation is more cost-effective if greater than 23% of sentinel node biopsies are positive (16% reported), or if 5-year survival for observed patients is greater than 76% (69% reported).

CONCLUSIONS

Based on existing clinical evidence, sentinel node biopsy yields greater utility than excision alone and is cost-effective for patients presenting with solitary dermal melanoma.

Metastatic malignant melanoma of the inguinal lymph node with unknown primary lesion

Background. Malignant melanoma could present with metastasis with unknown primary (MUP) and this happens in 2-3% according to the studies. Around 90% of melanomas have cutaneous origin, but still there are melanomas that could be found in visceral organs or lymph nodes with unknown primary site. Spontaneous regression of the primary site could be an explanation. Case Report. We report a 58-year-old Caucasian male who presented with a right sided swelling in the inguinal region. Surgery was performed and biopsy showed metastatic malignant melanoma. No cutaneous lesions were identified by history or physical examination. Work up could not detect the primary lesion and patient was started on radiotherapy and immunotherapy. Conclusion. We present a case of malignant melanoma of unknown primary presenting in an unusual place which is the inguinal lymph node. Theories try to explain the pathway of development of such tumors and one of the theories mentions that it could be a spontaneous regression of the primary cutaneous lesion. Another theory is that it could be from transformation of aberrant melanocyte within the lymph node. Prognosis is postulated to be better in this case than in melanoma with a known primary.