Reflectance confocal microscopy characteristics for melanocytic nevi

Morphological characterization of nevi on the caruncle conjunctiva under in vivo confocal microscopy

Objective

This study aimed to investigate the microscopic structure and characteristics of nevi on the conjunctiva of the lacrimal caruncle by in vivo confocal microscopy.

Methods

In total, four patients with nevi growing on the lacrimal caruncle conjunctiva were recruited. The morphological characteristics of the nevi were evaluated by in vivo confocal microscopy before excision surgery; the results were compared with histopathological analyses of the surgical specimens.

Results

The nevi of the four patients were all located at the conjunctiva of the lacrimal caruncle, with a slightly nodular surface, mixed black and brown color, and clear boundary. The nevi were round and highly protruded on the surface of the lacrimal caruncle, with an average diameter of 4.5 ± 1.29 mm. Under in vivo confocal microscopy, the pigmented nevus cells on the conjunctiva of the lacrimal caruncle were observed to be clustered in nests with irregular boundaries. The cells were round or irregular, with clear cell boundaries, hyper-reflective at the periphery, with low reflectivity in the center. Vascular crawling was observed in some regions. Histopathological analysis showed that nevus cells were roughly equal in size and distributed in a nodular pattern. Melanin granules were observed in the cytoplasm. No atypia or mitotic figures of the cells were found.

Conclusion

This study revealed that the microstructure of nevi growing on the conjunctiva of the lacrimal caruncle can be identified by in vivo confocal microscopy.

Application and challenge of reflectance confocal microscopy in the diagnosis of pigmented nevus

OBJECTIVE

To investigate the application and challenge of reflectance confocal microscopy (RCM) in the diagnosis of pigmented nevus.

METHOD

A total of 997 patients with clinical diagnosis of pigmented nevus were included in the study, and RCM imaging was performed on the lesion of each patient. A biopsy was performed in 78 of these patients for histological diagnosis. We retrospectively analyzed the results of RCM diagnosis and histological diagnosis and then found the RCM characteristics of the histologically confirmed lesion.

RESULTS

According to the RCM images, 823 of the 997 (82.55%) patients were diagnosed with pigmented nevus, while 113 (11.33%) were not diagnosed by dermatologists using RCM. Of the 78 biopsy lesions, 36 of the 46 (78.26%) cases diagnosed with pigmented nevus were consistent with histological diagnosis, while three were rediagnosed with dermatofibromas, four were seborrheic keratosis, one was malignant melanoma in situ, and two were lentigo.

CONCLUSION

RCM exhibits a high diagnostic accuracy for patients with clinical diagnosis of pigmented nevus. However, due to the limitation of RCM scanning depth and the commonality of the microscopic characteristics of related diseases, RCM still faces certain challenges in the diagnosis of pigmented nevus.