From the Guidelines
Blue nevi are benign lesions that do not require treatment unless there are concerns about appearance or changes that might suggest malignancy, and any suspicious changes warrant prompt medical attention to rule out melanoma or other skin cancers. When evaluating a blue nevus, it is essential to consider the 'ABCD rule' for suspicious lesions, which includes Asymmetry, Border irregularities, Colour heterogeneity, and Dynamics 4, as outlined in the ESMO clinical practice guidelines for diagnosis, treatment, and follow-up of cutaneous melanoma 1. Some key points to consider when evaluating blue nevi include:
- The 'ugly duckling' concept, which helps to identify melanomas by recognizing that naevi in the same individual tend to resemble one another, and melanomas often do not fit the individual's naevus pattern 1
- Dermoscopy by an experienced physician, which enhances diagnostic accuracy [II, B] 1
- The importance of a full-thickness excisional biopsy with a minimal side margin for diagnosis, with processing by an experienced pathology institute being mandatory 1
- The need for mutation testing for treatable mutations in patients with advanced disease, such as unresectable stage III or stage IV, and highly recommended in high-risk resected disease stage IIc, stage IIIb–IIIc [V, A] 1 In rare situations, melanomas may derive from dermal melanocytes, including malignant blue naevus 1. It is crucial to prioritize the patient's morbidity, mortality, and quality of life when making decisions about blue nevi, and any concerns or suspicious changes should be evaluated promptly by a dermatologist.
From the Research
Definition and Characteristics of Blue Nevus
- Blue nevus is a melanocytic tumor that can display a variety of different clinicopathological characteristics 2
- It is a heterogeneous group of lesions that can be classified into defined subtypes, including common blue nevi and cellular blue nevi 2
- Blue nevi can be found in the skin, but extracutaneous presentations, including the ocular surface, are rare 3
Clinical Features and Diagnosis
- Blue nevi of the ocular surface are rare and can be clinically similar to primary acquired melanosis or melanoma 3
- The clinical characteristics of blue nevi include a deeply pigmented lesion, often found on the bulbar conjunctiva, tarsal conjunctiva, or fornix 3
- Pathologic features of blue nevi are consistent with simple blue nevi or cellular blue nevus, and can be diagnosed through excisional biopsy and histopathological examination 3
Malignant Blue Nevus
- Malignant blue nevus (MBN) is a rare cutaneous tumor with a close biological resemblance to malignant melanoma 4
- MBN can spread to regional lymph nodes, and sentinel lymph node biopsy is a powerful staging tool for identifying occult metastatic nodal disease 4
- The management of MBN includes wide local excision and sentinel lymph node biopsy, with complete lymph node dissection if nodal metastasis is found 4, 5
Persistence and Recurrence
- Blue nevi can persist and recur, with a mean interval of 2.7 years from initial biopsy to biopsy of the recurrent lesion 6
- The recurrence of blue nevi can extend beyond the scar of the original excision, and can demonstrate atypical histologic features, but this does not necessarily indicate malignant transformation 6