Blue Nevi of the Ocular Surface: Clinical Characteristics, Pathologic Features, and Clinical Course

Abstract

Purpose: Blue nevus is a melanocytic tumor that is commonly found in the skin. Extracutaneous presentations, including the ocular surface, are rare. As such, the purpose of this study was to characterize the clinical features and clinical course of congenital melanocytic tumor (blue nevus) of the conjunctiva.

Design: Retrospective, noncomparative case series.

Participants: Twenty-one patients with 23 blue nevi of the ocular surface that were excised surgically between 2000 and 2016.

Methods: Chart review of patients identified from a database search of the Florida Lions Ocular Pathology Laboratory records. Pathologic diagnoses were confirmed by 2 pathologists (S.R.D. and G.E.). All specimens were bleached and, tissue permitting, stained using SOX10 (MilliporeSigma, Darmstadt, Germany) and CD68 (Leica Biosystems, Nussloch, Germany).

Main outcome measures: Clinical characteristics, pathologic features, and clinical course.

Results: Mean age of the population was 55±15 years; 71.4% (n = 15) were white and 57.1% (n = 12) were men. One patient had 3 lesions, for a total of 23 lesions examined. Clinically, 13 lesions were on the bulbar conjunctiva, 3 were on the tarsal conjunctiva, 3 were in the fornix, 2 were caruncular, 1 was episcleral, and 1 was at the limbus. Before excision, 8 patients were thought to have primary acquired melanosis, 4 with concern for primary conjunctival melanoma, and 1 thought to have metastatic disease from a plantar melanoma. Five lesions were thought to be benign, and in 8 patients, the lesions were identified incidentally after other ocular surgeries, with no diagnosis of the lesions before excision. Pathologic features were consistent with simple blue nevi in 21 lesions and cellular blue nevus in 2 lesions. No malignant transformations were noted in any patient over the mean 20.2-month follow-up period (range, 2 weeks-103 months).

Conclusions: Blue nevus is a rare deeply pigmented congenital melanocytic lesion with a benign clinical course that can appear clinically similar to primary acquired melanosis or melanoma.

Figure 1

Images from a 71 year old white Hispanic male A. Slit lamp photograph showing moderately pigmented lesions in the forniceal and adjacent palpebral and bulbar conjunctiva (arrow). B. Photomicrograph reveals densely pigmented spindled melanocytes containing copious intracytoplasmic pigment, consistent with blue nevus (arrow) (stain, hematoxylin–eosin; original magnification, ×200). C. Photomicrograph demonstrates removal of melanin pigment with bleach and morphologically benign dendritic cells lacking prominent nucleoli (stain, permanganate bleach; original magnification, ×200). D. Photomicrograph demonstrating SOX10 staining (arrow) within the dendritic pigmented melanocytes (stain, SOX10 immunostain with red chromagen; original magnification, ×400) E. Photomicrograph demonstrating CD68 positive melanophages (arrow) interspersed with the dendritic melanocytes (stain, CD68 immunostain with red chromagen; original magnification, ×400).

Figure 2

Distribution of the 23 blue nevi on the ocular surface in this series. Of 23 lesions, 5 were nasal (21.7%), 2 supero-nasal (8.7%), 1 infero-nasal (4.3%), 1 temporal (4.3%), 3 infero-temporal (13%) and 2 were superior (8.7%). Other lesion locations including 3 on palpebral conjunctiva (13%), 2 on the caruncle (8.7%), and 3 in the inferior fornix (13%). One lesion (4.3%) was in an unknown quadrant, found incidentally in a specimen taken during retinal detachment surgery.

Figure 3

Images from a 61 year old white non-Hispanic female A. Slit lamp image of the right eye showing a darkly pigmented, nodular lesion at the plica semilunaris which had been present for 20 years. Melanoma was suspected prior to removal. B. Photomicrograph revealing plump variably spindle shaped melanocytes and numerous melanophages (arrow) consistent with blue nevus (stain, hematoxylin–eosin; original magnification, ×200). C. Photomicrograph demonstrates removal of the melanin pigment with bleach and morphologically benign variably dendritic cells lacking prominent nucleoli. (stain, permanganate bleach; original magnification, ×200). D. Photomicrograph demonstrating SOX10 staining (arrows) within the dendritic pigmented melanocytes (stain, SOX10 immunostain with red chromagen; original magnification, ×200). E. Photomicrograph demonstrating CD68 positive melanophages (arrow) interspersed with the dendritic melanocytes (stain, CD68 immunostain with red chromagen; original magnification, ×200).

Figure 4

Images from a 79 year old white Hispanic female A: Slit-lamp photograph of the right eye showing a dark brown, flat lesion. Metastasis from a known plantar melanoma was suspected prior to removal. B: Photomicrograph demonstrates heavily pigmented dendritic shaped melanocytes and melanophages within the substantia propria (arrow) consistent with a blue nevus (stain, hematoxylin–eosin; original magnification, ×200). C: Photomicrograph demonstrates removal of melanin pigment with bleach and morphologically benign dendritic melanocytes and macrophages (stain, permanganate bleach; original magnification, ×200). D: Photomicrograph demonstrating SOX10 staining (arrow) within the dendritic shaped melanocytes (stain, SOX10 immunostain with red chromagen; original magnification, ×200). E: Photomicrograph demonstrating CD68 positive melanophages (arrow) interspersed with the dendritic melanocytes (stain, CD68 immunostain with red chromagen; original magnification, ×200).

Figure 5

Images from a 58 year old white non Hispanic female with a lesion on the tarsal conjunctiva A. Photomicrograph demonstrating densely pigmented plump dendritic shaped melanocytes and melanophages within the substantia propria (stain, hematoxylin-eosin ; original magnification, ×200). B. Photomicrograph demonstrating removal of melanin pigment with bleach and morphologically benign variably dendritic cells lacking prominent nucleoli (stain, permanganate bleach; original magnification, ×200). C. Photomicrograph demonstrating SOX10 (arrows) staining within the dendritic pigmented melanocytes (stain, SOX10 immunostain with red chromagen; original magnification, ×200). D. Photomicrograph demonstrating CD68 positive melanophages (arrow) interspersed with the dendritic melanocytes (stain, CD68 immunostain with red chromagen; original magnification, ×200).