Desmoplastic melanoma: a review of its pathology and clinical behaviour, and of management recommendations in published guidelines

Abstract

Desmoplastic melanomas are uncommon. Their behaviour differs from that of other melanoma subtypes; therefore, management guidelines for non-desmoplastic melanomas may not be applicable. This review sought to examine all available evidence relating to the behaviour and management of desmoplastic melanomas, based on review of all relevant English-language publications, and to critically assess the recommendations for their management in current published melanoma management guidelines. Compared with other melanoma subtypes, patients with 'pure' desmoplastic melanomas (where ≥90% of the invasive melanoma is of desmoplastic melanoma subtype) have much lower rates of sentinel node positivity and distant metastasis. Local recurrence rates are higher for desmoplastic melanomas, but resection margins wider than those recommended for non-desmoplastic melanomas have not been shown to be of benefit. Adjuvant radiotherapy reduces the risk of local recurrence when a satisfactory histological clearance (≥8 mm) cannot be achieved. Of 29 published melanoma management guidelines identified, only 11 specified management for desmoplastic melanomas, while seven simply stated that the feature should be reported. Desmoplastic melanoma is a unique melanoma subtype with biology that differs from that of other melanoma subtypes. It requires specific management strategies but few current guidelines address these.

Current and future approaches in the surgical management of T3b/T4 primary and locoregionally advanced melanoma

“…A very interesting trial is evaluating neoadjuvant pembrolizumab in patients with resectable stage II or III desmoplastic melanoma (S1512, NCT02775851). Desmoplastic melanoma appears to be particularly sensitive to single‐agent anti‐PD1 immunotherapy 23 and often presents with locally advanced disease due to the fact this variant is frequently amelanotic and lacks the typical recognition features associated with most other primary cutaneous melanoma subtypes 24 . The S1512 trial involved up to three doses of preoperative pembrolizumab before wide excision ± sentinel node biopsy or lymphadenectomy, respectively, for stage II or stage III desmoplastic melanoma.…”

“…Desmoplastic melanoma appears to be particularly sensitive to single-agent anti-PD1 immunotherapy 23 and often presents with locally advanced disease due to the fact this variant is frequently amelanotic and lacks the typical recognition features associated with most other primary cutaneous melanoma subtypes. 24 The S1512 trial involved up to three doses of preoperative pembrolizumab before wide excision ± sentinel node biopsy or lymphadenectomy, respectively, for stage II or stage III desmoplastic melanoma. Encouraging preliminary results of this trial were recently presented, 25 and our experience with this approach has indicated that there is a very high rate of pathologic complete response to neoadjuvant pembrolizumab in this melanoma subtype.…”

The Changing Epidemiology of Desmoplastic Melanoma

“…Desmoplastic melanoma (DM) is regarded as an uncommon form of melanoma that occurs on the head and neck of older people (median age 60–70 years), occurring more often males ( 1 ). Few epidemiological studies of pure DM (≥ 90% uniform desmoplasia) exist, and even fewer have reviewed contemporary DM patients.…”

Neuropathy as an early warning sign of desmoplastic neurotropic melanoma of the head

“…6,7 However, local recurrences are more frequent because of prevalent perineural spread 5 and often difficult complete excision. 7 Neuropathy has rarely been reported and then mostly in advanced tumour recurrences. 8 In any case, sensory deficits and paresis of peripheral nerves have not been reported as early prodromal signs of DM.…”

“…6 Desmoplastic melanoma metastasizes less frequently into the lymph nodes 5 and melanoma-specific survival appears to be longer than for other types of melanoma. 6,7 However, local recurrences are more frequent because of prevalent perineural spread 5 and often difficult complete excision. 7 Neuropathy has rarely been reported and then mostly in advanced tumour recurrences.…”