The clinico-pathological spectrum of plaque-type blue naevi and their potential for malignant transformation

AIMS

Plaque-type blue naevi are rare melanocytic tumours presenting as large, pigmented plaques at birth or during childhood. There is a risk for malignant transformation, but no larger comprehensive studies exist and the diagnosis is challenging, especially on limited biopsy material. The aim is to describe the clinicopathological features and behaviour of the disease more comprehensively.

METHODS AND RESULTS

We retrieved eight plaque-type blue naevi, presenting as large, pigmented plaques (median = 7 cm; range = 3-26) most frequently affecting the scalp (four) followed by the cheek, arm, abdominal wall and gluteal cleft (one each), with a slight female predilection. Median age at time of biopsy was 39.5 years (range = 15-90), but three tumours had been present at birth and one since childhood. Histopathologically, the tumours were poorly circumscribed and composed of cellular fascicles of uniform spindle cells in a background of variably prominent pigmented dendritic cells affecting dermis and subcutaneous tissues. The majority had mutations in GNAQ. One tumour showed malignant transformation, characterised by an expansile nodule of pleomorphic epithelioid melanocytes with rhabdoid morphology, high mitotic activity and areas of necrosis. This patient developed metastatic melanoma to lymph nodes. All patients are alive with a median follow-up of 60 months.

CONCLUSION

Plaque-type blue naevi are diagnostically challenging tumours with risk for malignant transformation. Awareness and familiarity with the salient clinicopathological features are necessary for reliable diagnosis, and long-term clinical follow-up is required to monitor for malignant transformation.

Surgical Therapy of Congenital Nevi in the First Year of Life-Psychological Impact on Parents

BACKGROUND

The birth of a child with a congenital melanocytic nevus (CMN) can lead to distress in the parents. Surgical treatment of CMN can begin in infancy.

OBJECTIVES

To provide insight into the perspective of parents of children with CMN regarding their experienced psychological burden and motivation to undergo surgery as well as their satisfaction.

METHODS

Retrospective analysis of patient data of infants (< 1 year of age), who were surgically treated by power stretching for CMN using subcutaneous infiltration anesthesia (SIA) from 01/01/2020 to 08/31/2021. To evaluate the parent's motivation and psychological burden during the surgical treatment of their child, a questionnaire was designed to interview them in a standardized telephone-based interview.

RESULTS

Out of 45 interviewed parents, 62.2% indicated "severe" or "very severe" distress at the time of their child's birth. Distress was mostly reduced by information about diagnosis and treatment (n = 34) and treatment-progress (n = 27). Stigmatization was experienced by 35.6% of parents. 84,5% of parents were highly satisfied with early initiation of surgical therapy. 69% felt "very satisfied" or "satisfied" with the outcome of surgery. Motivation for surgical therapy was concern about malignant transformation of the, possible stigmatization of the child due to the nevus, while most of the parents (73.3%) mentioned both.

CONCLUSIONS

Surgical treatment of CMN by power stretching in SIA in infancy is associated with high levels of satisfaction among the children's parents. Early initiation of surgical therapy and education about the diagnosis can reduce the psychological burden of the parents and can prevent psychosocial problems in affected children.

Management of Congenital Melanocytic Naevi in Children: A French National Survey Using Clinical Vignettes

Management of congenital melanocytic naevi in childhood may vary depending on the habits and experience of the treating clinician. The aim of this study was to assess current practice and determinants of surgical excision decision-making among French physicians. A national survey was conducted among dermatologists, paediatricians and surgeons, using clinical vignettes illustrating 29 scenarios. The primary outcome was the decision to perform surgical excision in each vignette. Of the 11,310 decisions made by the 390 participants (257 dermatologists, 35 surgeons, and 98 paediatricians) surgical excision was chosen in 33% of cases. The stated motivations for performing surgical excision were: melanoma risk, aesthetic/psychosocial risk, or both, in 39%, 34% and 27% of cases, respectively. Physicians with a higher level of experience in oncodermatology were more likely to opt for surgical excision. The age of the child, the size of the congenital melanocytic naevi, and the visibility of the lesion had no influence on the decision to perform surgical excision.