Desmoplastic malignant melanoma of the lip: a report of 6 cases and review of the literature

Local Recurrence Rates After Excision of Desmoplastic Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Few prospective studies have evaluated local recurrence rates (LRR) after excision of desmoplastic melanoma (DM); however, several retrospective studies have reported high LRR.

OBJECTIVE

To determine LRR after excision of DM and evaluate factors affecting LRR.

MATERIALS AND METHODS

Systematic review of the PubMed, Embase, and Web of Science databases was performed to identify studies reporting local recurrence after excision of DM with conventional wide local excision (WLE), Mohs micrographic surgery (MMS), or staged excision (SE). Meta-analysis was performed to calculate summary LRR and pooled risk ratios (RR).

RESULTS

Literature search identified 4 studies evaluating MMS or SE (total n = 61 DM). 53 studies assessed WLE ( n = 3,080) and were analyzed quantitatively. The overall LRR after WLE of DM was 21% (95% CI, 0.16-0.28; n = 2,308). Local recurrence rate was higher with positive/unknown histologic excision margins (49%, 95% CI, 0.25-0.74; n = 91) versus negative histologic margins (11%, 95% CI, 0.07-0.17; n = 1,075; [ p < .01]). Neurotropism was also associated with increased LRR (RR, 1.79; 95% CI, 1.34-2.38, p < .01; n = 644).

CONCLUSION

DM has high LRR after WLE. Local recurrence risk was greatest with positive excision margins, indicating the importance of achieving negative microscopic margins. Greater study of MMS and SE for DM is required.

Desmoplastic Melanoma of the Head and Neck: Incidence and Survival, 1992-2013

Objective To describe the epidemiological characteristics and survival of desmoplastic melanoma of the head and neck (DMHN) and discuss the factors influencing survival variation among DMHN, DM of other sites (DMnHN), and conventional melanoma of the head and neck (CMHN). Study Design Retrospective cohort study. Setting Surveillance, Epidemiology, and End Results (SEER) database (years 1992-2013). Subjects and Methods Incidence and survival data for 1095 patients with DMHN, 1139 patients with DMnHN, and 40,257 patients with CMHN were obtained. Kaplan-Meier and Cox proportional hazards regression models were used to calculate survival outcomes. Results Patients with DMHN were diagnosed at greater Breslow thickness ( P < .001), stage ( P < .001), and Clark's level ( P < .001) compared to DMnHN and CMHN. Kaplan-Meier survival analysis demonstrated disease-specific survival (DSS) at 5 and 10 years for DMHN to be 80.5% and 74.7%, respectively, compared with 89.1% and 86%, respectively, for DMnHN and 88.1% and 83%, respectively, for CMHN (log-rank test; P < .001). On multivariate Cox regression analysis, age at diagnosis ( P < .001), Breslow depth >4.00 mm ( P = .006), lymph node status ( P < .001), and presence of ulceration ( P < .001) were found to be independent predictors of DSS for DMHN. Conclusion The increasing incidence and poor survivability of DMHN compared to DMnHN and CMHN are parsimoniously explained by the later stage of disease and depth of invasion at diagnosis, highlighting the importance of improved diagnosis and awareness of DMHN.

Primary Malignant Melanoma of the Lip: A Report of 48 Cases

PURPOSE

Lip melanoma (LM) is a rare malignant tumor and well-established treatment protocols for it are in short supply. The objective of this study was to evaluate the outcome of treatment modalities and explore the prognostic factors.

PATIENTS AND METHODS

A retrospective chart review was performed on 48 patients with primary LM treated in the authors' hospital from January 1992 to November 2013. The clinical characteristics and treatment modalities were identified and correlated with the outcomes.

RESULTS

The 5-year overall survival (OS) rate was 56.1%, and the rate of cervical lymph node (CLN) metastasis was 46% (22 of 48). A tumor of at least 4 cm (P = .001), nodular types (P = .003), and CLN (P < .0001) were independent prognostic factors for OS. Twenty-five patients died during follow-up, mainly from to neck recurrence (14 of 25). Chemotherapy significantly improved the 5-year OS rate in patients with stage IV LM (P = .03), but not in those with stage III (P = .8).

CONCLUSIONS

LM has a lower CLN and distant metastasis rate and a better prognosis than other oral mucosal melanomas. A long history of melanin pigmentation is a dangerous sign for all patients, and smoking seems to be associated with LM in male patients. Tumor size (≥4 cm), nodular type, and CLN positivity are poor prognostic factors. A wide excision with close observation is advocated as the primary treatment for stage III LM. Adjuvant chemotherapy is useful for patients with stage IV cancer, but not for those with stage III.

Incidence and survival of desmoplastic melanoma in the United States, 1992-2007

BACKGROUND

Desmoplastic melanoma (DM) represents a relatively rare malignancy. The aim of this study was to describe the incidence and survival of DM in the United States.

METHODS

Incidence and survival data were obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program, 1992-2007. Kaplan-Meier and Cox proportional hazards regression methods were used to calculate the survival rates and hazard ratios for DM-specific death.

RESULTS

We identified 1129 DM patients from SEER 13 registries, with 64% in men, 37% in women and most (96.8%) occurring in White populations. The incidence rates per 1,000,000 were 1.3 (female), 3.0 (male) and 2.0 (both). The annual percentage change for incidence was 4.6 (95% confidence interval: 2.9-6.5) from 1992 to 2007. The 5-year and 10-year DM-specific survival rates from SEER 17 registries were 84.8 and 79.2%. The 5-year DM-specific survival rates by stage ranged from 90.9% (local) to 51.5% (distant). Independent predictors of mortality from DM included age, anatomic site, thickness, ulceration, lymph node and surgery.

CONCLUSIONS

The incidence of DM has been increasing steadily over the past 15 years. Older age, anatomic site of the head and neck, tumor thickness >2 mm, ulceration, lymph node involvement and non-receipt of surgery are associated with lower survival.

Desmoplastic melanoma: a diagnostic trap for the unwary

Desmoplastic melanoma (DM) is an uncommon type of spindle cell melanoma in which the malignant cells are separated by collagen fibres or fibrous stroma. DM is prone to misdiagnosis because of unfamiliarity with its often bland appearance and dissimilarity to other conventional types of melanoma. It displays variable cytological atypia, cellularity and stromal fibrosis and more often than not has an accompanying atypical junctional component. Neurotropism is a common associated feature (in at least 30% of cases) and when it occurs such tumours are termed 'desmoplastic neurotropic melanomas' (DNM). The neurotropism may be perineural or intraneural and often extends beyond the desmoplastic component. In addition, some DMs show evidence of neural differentiation ('neural transformation'). DM may also present as a recurrence or occasionally as a metastasis from other types of melanoma. A high index of suspicion and knowledge of its often subtle morphological appearance are necessary to avoid misdiagnosis.