Malignant Transformation of a Miescher Nevus: An Exceptional Case with Dermoscopic Correlation
EADV 2026, Vienna, Avusturya, 30 Eylül - 03 Ekim 2026, (Yayınlanmadı)
- Yayın Türü: Bildiri / Yayınlanmadı
- Basıldığı Şehir: Vienna
- Basıldığı Ülke: Avusturya
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
Introduction
Miescher nevi represent a distinct subtype of intradermal nevus that predominantly occurs on the face,
particularly in the malar region. Clinically, they present as dome-shaped skin-colored to light-brown
nodules, often containing terminal hairs, and tend to become more prominent with age (Greco et al.,
2020).
Cutaneous melanoma is the most aggressive form of skin cancer and may arise either de novo or from a
pre-existing nevus. Approximately 20–30% of melanomas are nevus-associated. (Bevona et al., 2003;
Cymerman et al.).
Importantly, nevus-associated melanomas most commonly arise from junctional or compound nevi,
whereas melanoma developing within a purely intradermal nevus is considered exceptionally rare.
Previously reported cases have predominantly described melanoma arising at the periphery of
intradermal nevi, rather than originating directly within them (Ledić Drvar et al., 2023). However, rare
reports have documented melanoma developing entirely within intradermal nevi without a junctional
component (Benisch et al., 1980; Hashiro et al., 1998).
Herein, we present a rare case of invasive melanoma arising within a long-standing Miescher-type
intradermal nevus on the right malar region of a 66-year-old woman.
Case Presentation
A 66-year-old woman presented with recent changes in a long-standing nevus on the right malar region.
The lesion had been present for approximately 50 years and had remained stable until three months
before admission, when progressive darkening at the inferior pole was noted. The patient denied
bleeding or ulceration and reported the presence of terminal hairs since the initial appearance of the
lesion.
Her medical history was significant for diabetes mellitus and hypertension, with no history of
immunosuppression. There was no personal or family history of melanoma. She had not regularly used
sunscreen, and her Fitzpatrick skin type was III.
Dermatological examination revealed a skin-colored nodular lesion with focal dark brown pigmentation
and terminal hairs. No regional lymphadenopathy was detected. Dermoscopic evaluation demonstrated
an atypical blotch in the inferior portion of the lesion, with a milky-red, structureless area, polymorphic
vessels, and shiny white streaks around, raising suspicion of malignant transformation (Figure 1). The
clinical differential diagnosis included intradermal melanocytic nevus and malignant melanoma.
The lesion had been excised at an external center and was subsequently re-evaluated at our institution.
Histopathological examination confirmed superficial spreading melanoma with a Breslow thickness of 1.5
mm (Clark level III) and a mitotic rate of 5/mm²
, without ulceration or evidence of lymphovascular or
perineural invasion (Figure 2). The melanoma arose in association with a pre-existing intradermal nevus,
and surgical margins were clear.
Sentinel lymph node biopsy following lymphoscintigraphy revealed no metastatic involvement. A
subsequent wide local excision showed no residual tumour. According to the AJCC 8th edition, the patient
was classified as stage IB melanoma(Gershenwald et al., 2017).No adjuvant therapy was indicated. To rule out the metastasis of a primary melanoma from another
location, the patient was screened with computed tomography, showing no evidence of any primary or
metastatic melanoma.
Conclusion
Melanoma arising within a purely intradermal (Miescher-type) nevus represents an exceptionally rare
event. This case underscores that even long-standing, clinically benign-appearing intradermal nevi can
undergo malignant transformation. In our patient, the recent asymmetric darkening of the lesion served
as a crucial warning sign. Importantly, following careful clinical and dermoscopic assessment of lesions
with recent or rapidly evolving changes, prompt biopsy should be performed in cases of suspicion and
not delayed.