Histological criteria for grading of atypia in melanocytic conjunctival lesions

Conjunctival Melanoma: A Clinical Review and Update

Conjunctival melanoma (Co-M) is an aggressive, invasive eye and eyelid cancer. Its global incidence of ~1 in a million is increasing at a rate ratio of ~1.4, but this rises sharply in over 65-year-olds. Although rare, Co-M has a devastating impact on the lives of those who develop it. Co-M is often misdiagnosed or overlooked, leading to vision loss either from the destructive effects of the tumour or side effects of therapy, facial disfigurement from radical surgery, and death from metastases. Due to its rarity, there is limited evidence for diagnosis and management; hence, there is no standardised treatment and not all cases are referred to a specialised ocular oncology centre. Recent progress in cancer immunology and genetics have revolutionised the treatment of cutaneous melanomas, which share some similarities to Co-M. Importantly, a better understanding of Co-M and its precursor lesions is urgently needed to lead to the development of novel targeted and immunotherapies both for local tumour control and disseminated disease. This review aims to provide a comprehensive clinical overview of the current knowledge regarding Co-M, its epidemiology, pathogenesis, presentation, diagnosis and recent changes in the classification of its precursor lesions, management, and recent advances in novel biological therapies for personalised treatment of this disease.

Primary acquired melanosis/melanoma: utility of conjunctival map biopsy

AIM

To assess the role of map biopsy in patients with conjunctival primary acquired melanosis (PAM)/melanoma.

METHODS

Retrospective case series of 400 conjunctival biopsy samples of 51 unique patients in a tertiary referral centre.

RESULTS

Each patient underwent one diagnostic biopsy and several additional map biopsies (range 2-7) providing a total of 400 samples for the analysis (55 diagnostic biopsies, 345 map biopsies). The median age was 63 years old (range 20-88) with women representing 67% of the cases. Histopathological findings were graded as negative for melanosis/normal (grade 0), melanosis without atypia (grade 1), melanosis with mild atypia (grade 2), melanosis with severe atypia (grade 3) or invasive melanoma (grade 4). Clinicopathologic concordance was observed in the majority of the map biopsies (313, 91%) (positive: clinical+/path+ (57,17%), negative: clinical-/path- (256, 74%)). Three discordant samples (clinical-/path+) represented PAM sine pigmento. The histopathological spectrum of atypia was absent (40, 73%) or limited (11, 20%) in the majority of cases with tendency to cluster as low-grade or high-grade atypia. Map biopsy led to the identification of six patients (11%) with severe atypia, requiring topical mitomycin (MMC). Similarly, in 29 cases, periodic observation without topical MMC was recommended. One case of invasive melanoma transformation occurred in the MMC-treated group.

CONCLUSIONS

Map biopsy enhances overall assessment of the anatomic and pathologic extent, impacting use of adjuvant topical chemotherapy. In absence of map biopsy, it would be impossible to diagnose PAM sine pigmento. Additional corroborative work is needed to validate our observations.

Validation of the Newly Proposed World Health Organization Classification System for Conjunctival Melanocytic Intraepithelial Lesions: A Comparison with the C-MIN and PAM Classification Schemes

PURPOSE

We sought to compare the sensitivity, specificity, accuracy, and interobserver agreement of the two most commonly used classification systems for conjunctival melanocytic intraepithelial lesions with the new World Health Organization (WHO) classification.

DESIGN

Retrospective case series and evaluation of classification systems.

METHODS

We reviewed the pathology and medical records of all patients who underwent a primary biopsy procedure for conjunctival primary acquired melanosis (PAM) at Wills Eye Hospital between 1974 and 2002 who had ≥36 months of follow-up. Data collected included age, sex, clinical findings, recurrence, and progression to melanoma. Twelve ophthalmic pathologists analyzed scanned hematoxylin and eosin-stained virtual microscopic slides using 3 classification systems: PAM, conjunctival melanocytic intraepithelial neoplasia, and the WHO 4th edition classification of conjunctival melanocytic intraepithelial lesions. Observer agreement, sensitivity, specificity, and diagnostic accuracy of each classification system were assessed.

RESULTS

There were 64 patients who underwent 83 primary excisions with cryotherapy for conjunctival PAM who had adequate tissue for histopathologic evaluation. The interobserver agreement in distinction between the low- and high-grade lesions was 76% for PAM, 67% for conjunctival melanocytic intraepithelial neoplasia, and 81% for WHO classification system. Low-grade lesions provided the greatest interpretative challenge with all 3 classification systems. The 3 classification systems had comparable accuracy of 81%-83% in their ability to identify lesions with potential for recurrence.

CONCLUSIONS

This study highlights the comparable strengths and limitations of the 3 classification systems for conjunctival melanocytic intraepithelial lesions and suggests that the simplified WHO classification scheme is appropriate for evaluation of these lesions.

Conjunctival Melanoma - Epidemiological Trends and Features

Conjunctival melanoma is a rare but sight and life threatening malignancy. It accounts for 2%-5% of all ocular tumours and 5%-7% of all ocular melanomas with an incidence of 0.2-0.8 per million in the Caucasian population with rare cases reported in the non-Caucasians. In recent decades the incidence of uveal melanoma has been relatively stable whilst conjunctival and cutaneous melanoma have shown increasing incidence which may be connected to the result of environmental exposure to ultraviolet light. The dissimilarity in incidence between light and dark pigmented individuals observed in conjunctival melanomas compared to uveal and cutaneous melanomas may be related to differences in their histological structures and genetic profile. Recent molecular biological studies support the fact that each type of melanoma undergoes its own molecular changes and has characteristic biological behaviour. Further studies are required for each type of melanoma in order to ascertain their individual etiology and pathogenesis and based on this knowledge develop relevant preventative and treatment procedures.

Inflamed conjunctival nevi: histopathological criteria

Inflamed conjunctival nevi (ICN) may suggest malignancy because of their rapid growth and atypical histology. The objective of this study was to characterize the diagnostic features of ICN. A retrospective, nonrandomized study of 13 patients with ICN was conducted. A scoring method was developed based on histology and immunopathological parameters. The presence of epithelial solid or cystic inclusions and the preservation of goblet cells are consistent with a benign melanocytic lesion. Periodic acid-Schiff stain and immunohistochemistry to identify the epithelial component prove helpful in the differential diagnosis for melanoma. Polyclonal lymphoid infiltrate and benign cytological features of ICN exclude a diagnosis of lymphoma. Despite the presence of immunoglobulin 4-positive plasma cells in the lesions, ICN does not meet the diagnostic criteria for immunoglobulin 4-related disease. Most patients with ICN are young. The treatment for ICN is complete excision, and the prognosis is excellent.

Conjunctival melanoma: a review of conceptual and treatment advances

The aim of this study was to review the available literature and identify recent advances in the classification and management of conjunctival melanoma (CM) for clinicians working in this field. English-based articles were identified using the MEDLINE^® database, and additional cited works not detected in the initial search were also obtained. Articles were assessed according to the Australian National Health and Medical Research Council levels of evidence criteria. Review of the literature indicated that the current classification and management of CM is predominantly based upon primarily nonrandomized, single-institution, retrospective case series. While these studies provide the basis for the recent seventh edition of the tumor node metastasis staging classification, this classification more accurately reflects the current knowledge of prognostic factors for CM. Application of this revised classification system together with prospective trials will provide the opportunity for future consistent and comparable data collection across centers, and it will improve the quality of evidence upon which current classification and management of CM is based. Furthermore, the high risk of local recurrence with current standard management suggests that adjuvant therapy, particularly mitomycin C and/or brachytherapy, may improve outcomes regardless of clinical staging. Finally, the use of sentinel lymph node biopsy may have significant benefit for a select group of CM patients.

Conjunctival Melanoma: A New Clinical and Therapeutical Approach

Melanoma involving the conjunctiva is extremely rare. Graver prognosis has been reported with primary conjunctival melanoma than with their cutaneous counterparts [Collin et al.: Aust N Z J Ophthalmol 1986;14:29–34]. Among conjunctival melanomas, two significant risk factors for tumour-related death have been identified: (i) age older than 55 years and (ii) unfavourable tumour location (caruncle, cornea, fornix, palpebral conjunctiva) [Werschnik and Lommatzsch: Am J Clin Oncol 2002;25:248–255]. Here we present a rare case of lentigo maligna involving the palpebral, bulbar conjunctiva and the caruncle. We describe dermoscopic patterns observed and the use of a novel ocular melanoma therapy with topical imiquimod.