Programmed Cell Death 1 Ligand 1 and Programmed Cell Death 1 Ligand 2 Are Expressed in Conjunctival Invasive Squamous Cell Carcinoma: Therapeutic Implications

Immunotherapy for Advanced Conjunctival Squamous Cell Carcinoma: Treatment Failures

PURPOSE

To review the treatment response of advanced conjunctival squamous cell carcinoma (SCC) to systemic immune checkpoint inhibitor (ICI) therapy at a single institution.

METHODS

A retrospective review of patients treated at a single institution from 2015 to 2024 was conducted to identify those with advanced conjunctival SCC who had been treated with ICI therapy. Advanced disease included patients with orbital invasion of tumors, unresectable disease, or metastatic disease. Computed tomography imaging and tumor mutational burden data were evaluated for all patients.

RESULTS

Five patients with advanced conjunctival SCC were treated with ICIs. All patients had the American Joint Committee on Cancer stage cT3N0M0. All patients had best corrected visual acuity in the affected eye of 20/30 or better at presentation. All patients progressed while on ICIs, with 3 ultimately requiring exenteration at a median time of 6 months from initial diagnosis. One patient had progressive metastatic disease, and one had direct intracranial extension. All patients had low tumor mutational burden.

CONCLUSIONS

Unlike prior reports demonstrating complete treatment response while on ICI therapy in patients with advanced conjunctival SCC, the current study demonstrates that 5 of 5 patients had disease progression while on ICI therapy. All patients also had low tumor mutational burden. Tumor mutational burden may be important in predicting disease response to ICI in patients with conjunctival SCC; however, given the small number of patients with conjunctival SCC treated with ICI to date, more data are needed to understand the role of ICIs in conjunctival SCC.

Immune Checkpoint Inhibitors in the Treatment of Ocular Surface Cancers: A Review

BACKGROUND

Immune checkpoint inhibitors (ICIs) have transformed cancer therapy by targeting key immune pathways such as PD-1, PD-L1, CTLA-4, and LAG-3 to enhance the immune system's ability to combat malignancies. Their use in treating ocular surface tumors is an emerging area of interest, particularly in conjunctival melanoma (CM) and ocular surface squamous neoplasia (OSSN). Some studies have indicated the potential of ICI's in sebaceous gland carcinoma (SeC), conjunctival lymphoma, and Kaposi sarcoma.

PURPOSE

This review aims to evaluate the role of ICIs in treating ocular surface tumors, focusing on their mechanisms of action, clinical outcomes, and therapeutic potential.

METHODS

A literature review was conducted by searching Pubmed for studies published between January 2014 and October 2024. Studies included were original research, clinical trials, case reports and series, and reviews.

RESULTS

ICIs, including pembrolizumab and nivolumab, have shown promising results in CM, achieving tumor regression and disease stabilization in advanced and metastatic cases. ICIs have also demonstrated efficacy in OSSN, particularly in lesions with high tumor mutational burden, with responses ranging from partial to complete resolution. Although clinical data for SeC and conjunctival lymphoma remain limited to isolated reports, these studies suggest a role for ICIs in managing refractory or advanced disease.

CONCLUSION

ICIs hold transformative potential in improving outcomes for ocular surface malignancies, particularly in cases where conventional treatments fail or pose significant morbidity. Despite their promise, challenges persist, including variable response rates, immune-related adverse events, and the need for reliable predictive biomarkers. Comprehensive prospective studies are necessary to refine the application of ICIs, optimize treatment strategies, and expand therapeutic options for these challenging cancers.

Ocular surface squamous neoplasia: Update on genetics, epigenetics and opportunities for targeted therapy

PURPOSE

The purpose of this review is to explore the molecular foundations of ocular surface squamous neoplasia (OSSN), focusing on the genetic and epigenetic aspects. While current management strategies include surgical excision and medical therapies, the understanding of OSSN's molecular basis remains limited, hindering the development of targeted treatments.

METHODS

A comprehensive MEDLINE search was conducted for literature published between January 1993 and October 2023. Only studies with original data on molecular, genetic, or epigenetic mechanisms, such as mutations, gene expression, and genetic predispositions were included. Articles were excluded if they focused solely on clinical management without addressing these factors, or if they were reviews, editorials, or opinion pieces.

RESULTS

The search yielded a total of 108 articles, out of which 39 articles met the criteria for further analysis. Investigations into OSSN have identified key DNA mutations in the TP53, HGF, EGFR, TERT, and CDKN2A genes, indicating common oncogenic pathways shared with other squamous cell carcinomas (SCCs). Significant epigenetic changes were identified, including DNA methylation, histone modifications, and altered miRNA expression patterns. Epigenetic dysregulation of critical tumor suppressors and oncoproteins, further highlight the complex genetic landscape of OSSN.

CONCLUSION

The molecular alterations identified in OSSN not only enhance our understanding of its biology but also have potential as novel biomarkers for early detection, prognostic evaluation, and as therapeutic targets. The identification of genetic and epigenetic markers in OSSN signifies progress towards personalized medicine approaches. Further studies and collaborative efforts are essential to validate these molecular markers and translate them into clinical practice, potentially revolutionizing OSSN management and improving patient outcomes.

Personalized treatment concepts in extraocular cancer

Background

The periocular skin is neoplasms-prone to various benign and malignant. Periocular malignancies are more aggressive and challenging to cure and repair than those in other skin areas. In recent decades, immunotherapy has significantly advanced oncology, allowing the autoimmune system to target and destroy malignant cells. Skin malignancies, especially periocular tumors, are particularly sensitive to immunotherapy. This technique has dramatically impacted the successful treatment of challenging tumors.

Main text

Extraocular cancers, including eyelid (basal cell carcinoma, squamous cell carcinoma, melanoma, merkel cell carcinoma), conjunctival tumors (conjunctival melanoma, ocular surface squamous neoplasia) and other rare tumors, are unique and challenging clinical situations. Several genetic alterations associated with the pathogenesis of these diseases have been identified, and molecular mechanism are essential for the development of the immunotherapy agents, such as Hedgehog pathway inhibitors (vismodegib and sonidegib) for basal cell carcinoma, BRAF/MEK inhibitors (vemurafenib, dabrafenib, and encorafenib) for melanoma, and immune checkpoint inhibitors (Avelumab, pembrolizumab) for Merkel cell carcinoma.

Conclusions

The optimal treatment for periocular skin cancer depends on the type and size of the tumor and whether it involves orbital and adnexal structures. Adjuvant and neoadjuvant therapy with chemotherapy-targeted therapies and immune checkpoint inhibitors should be considered based on tumor type, tumor molecular profile, expected response rate, and candidacy for systemic treatment.

Use of Cemiplimab, an Immune Checkpoint Inhibitor for Conjunctival Intraepithelial Neoplasia

PURPOSE

Immune checkpoint inhibitors (ICIs) have been recently introduced for the treatment of locally unresectable conjunctival squamous cell carcinoma. We present 2 cases with conjunctival intraepithelial neoplasia (CIN) who were treated with ICIs.

METHODS

A report of 2 cases with CIN who were treated with systemic cemiplimab (350 mg IV every 3 weeks).

RESULTS

A 70-year-old man was treated with cemiplimab for metastatic cutaneous squamous cell carcinoma. The pre-existing CIN continued to progress over the nasal bulbar conjunctiva and cornea, while the other metastatic sites, including parotid glands, and neck lymph nodes showed a complete response after 16 cycles of treatment. An 84-year-old woman had bilateral diffuse CIN involving bulbar and lower eyelid palpebral conjunctiva. Cemiplimab was started because of the extent of involvement. While the bulk of CIN was reduced, it progressed over the cornea and forniceal conjunctiva on OU after 10 cycles of treatment. Excisional biopsies of conjunctival lesions after cemiplimab confirmed CIN in both patients.

CONCLUSIONS

Although conjunctival squamous cell carcinoma tumors are reported to be highly responsive to ICIs, a similar effect has not been observed in 2 patients with CIN. Further studies are needed to evaluate ICIs in the management of CIN.

Histologic and Genomic Analysis of Conjunctival SCC in African and American Cohorts Reveal UV Light and HPV Signatures and High Tumor Mutation Burden

Purpose

Conjunctival squamous cell carcinoma (conjSCC) is more prevalent and aggressive in sub-Saharan African countries compared with the rest of the world. This study aims to compare the genomic, immunophenotypic, and histologic features between patients from the United States and Ethiopia, to identify etiopathogenic mechanisms and unveil potential treatment strategies.

Methods

We compared histologic features and mutational profiles using whole exome sequencing, high-risk human papillomavirus (HPV) status, PD-L1 expression, and tumor-infiltrating lymphocytes in conjSCC tumors of patients from Ethiopia (ETH; n = 25) and the United States (from MD Anderson [the MDA cohort]; n = 29). Genomic alterations were compared with SCCs from other anatomic sites using data from The Cancer Genome Atlas.

Results

Solar elastosis was seen in 78% of ETH and 10% of MDA samples. Thicker tumors had higher density of CD8+ and CD3+ cells. HPV status was similar between the cohorts (ETH = 21% and MDA = 28%). The mean tumor mutation burden (TMB) was significantly higher in conjSCC (3.01/Mb, log10) and cutaneous SCC compared other SCC subtypes. ETH samples had higher TMB compared to the MDA cohort (3.34 vs. 2.73). Mutations in genes associated with ultraviolet light (UV) signature were most frequently encountered (SBS7b = 74% and SBS7a = 72%), with higher prevalence in the ETH cohort, whereas SBS2 and SBS13 signatures were more common among MDA HPV+ conjSCCs.

Conclusions

Our findings suggest that UV exposure may play a major role in conjSCC, with a higher prevalence in the ETH cohort compared with the MDA cohort, where HPV also contributes.

Targeted therapy in ophthalmic oncology: The current status

There have been rapid advancements in the field of ocular oncology for the diagnosis and management of intraocular, adnexal, and orbital tumors. Targeted therapy is in the forefront of medical research in all fields including ocular oncology. Targeted therapy include drugs that target specific genetic mutations, pathways or proteins involved in the development of cancer. In contrast to traditionally used chemotherapy, drugs used in targeted therapy are highly specific for tumor cells and preserve the function of normal cells. This review aims to familiarize ophthalmologists with the drugs that are currently approved or undergoing clinical trials for use in ocular oncology. Targeted therapy is particularly useful for locally advanced or metastatic tumors, including but not limited to eyelid and periocular basal cell carcinoma, periocular cutaneous and conjunctival squamous cell carcinoma, ocular adnexal lymphoma, conjunctival melanoma, and uveal melanoma. The results are promising with improved survival outcomes and better tolerability than chemotherapeutic drugs.

Targeted Therapy and Immunotherapy for Advanced Malignant Conjunctival Tumors: Systematic Review

PURPOSE

To review the outcomes of targeted therapy and immunotherapy in advanced conjunctival tumors, including conjunctival squamous cell carcinoma, conjunctival melanoma, and conjunctival lymphoma.

METHODS

A Pubmed database systematic search was performed between January 1999 and December 2022. The literature search was limited to studies published in English.

RESULTS

This review included 142 patients with advanced malignant conjunctival tumors from 42 articles. In the conjunctival squamous cell carcinoma group, 2 cases of advanced conjunctival squamous cell carcinoma treated with epidermal growth factor receptor inhibitors showed significant tumor size improvement after 7.5 months of follow-up. Among 7 cases treated with systemic immunotherapy, 5 cases (72%) had complete response (CR), 1 case (14%) showed partial response (PR), and 1 case (14%) had stable disease (SD) after 16 months. In the conjunctival melanoma group, among 18 cases treated with combined v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated extracellular signal-regulated kinase inhibitors, 6 (33%) had CR, 5 (28%) had PR, 2 (11%) had SD, and 5 (28%) had progressive disease after 24.8 months of follow-up. Of 44 conjunctival melanoma cases treated with immunotherapy, 12 (28%) had CR, 9 (20%) had PR, 7(16%) had SD, and 16 (36%) had progressive disease after 14.2 months. Systemic Rituximab treatment for conjunctival lymphoma cases resulted in CR in 21 patients (63%), PR in 11 patients (33%), and SD in 1 patient (3%) after 20.5 months of follow-up. Intralesional Rituximab injections in 38 conjunctival lymphoma cases showed CR in 28 patients (75%), PR in 7 patients (19%), SD in 1 patient (2%), and progressive disease in 2 patients (4%) after 20.4 months of follow-up.

CONCLUSIONS

Despite limited clinical case reports and short-term follow-ups, targeted therapy and immunotherapy have shown promising results for advanced malignant conjunctival tumors.

MYO5A overexpression promotes invasion and correlates with low lymphocyte infiltration in head and neck squamous carcinoma

Head and neck squamous carcinoma (HNSC) poses a significant public health challenge due to its substantial morbidity. Nevertheless, despite advances in current treatments, the prognosis for HNSC remains unsatisfactory. To address this, single-cell RNA sequencing (RNA-seq) and bulk RNA-seq data combined with in vitro studies were conducted to examine the role of MYO5A (Myosin VA) in HNSC. Our investigation revealed an overexpression of MYO5A in HNSC that promotes HNSC migration in vitro. Remarkably, knockdown of MYO5A suppressed vimentin expression. Furthermore, analyzing the TCGA database evidenced that MYO5A is a risk factor for human papillomavirus positive (HPV+) HNSC (HR = 0.81, P < 0.001). In high MYO5A expression HNSC, there was a low count of tumor infiltrating lymphocytes (TIL), including activated CD4+ T cells, CD8+ T cells, and B cells. Of note, CD4+ T cells and B cells were positively associated with improved HPV+ HNSC outcomes. Correlation analysis demonstrated a decreased level of immunostimulators in high MYO5A-expressing HNSC. Collectively, these findings suggest that MYO5A may promote HNSC migration through vimentin and involve itself in the process of immune infiltration in HNSC, advancing the understanding of the mechanisms and treatment of HNSC.

Medical treatment for ocular surface squamous neoplasia

Ocular surface squamous neoplasia (OSSN) is the most common non-melanocytic tumour of the ocular surface. Surgical excision with wide margins using the "no-touch" method was originally the most popular treatment for OSSN. However, in the past two decades, the use of topical medications for OSSN treatment has gained a reputation amongst ophthalmologists for being an effective alternative to surgical excision. Furthermore, technological advancements, such as those seen in high-resolution optical coherence tomography (HR-OCT) for the anterior segment, have facilitated the diagnosis and monitoring of OSSN. When selecting a topical agent, interferon alpha-2b (IFNα-2b) and 5-fluorouracil (5-FU) are two of the gentlest medications used for OSSN and are often considered first line therapies due to their high-resolution rates and mild side effect profiles. Mitomycin C (MMC), on the other hand, has a highly toxic profile; therefore, while effective, in our hands it is considered as a second-line treatment for OSSN if the other modalities fail. In addition, newer and less studied agents, such as immune checkpoint inhibitors, retinoic acid, aloe vera, and anti-vascular endothelial growth factor have anti-neoplastic properties and have shown potential for the treatment of OSSN. We enclose an updated literature review of medical treatments for OSSN.

Human papillomavirus-related neoplasia of the ocular adnexa

Human papillomaviruses (HPV) are involved in approximately 5% of solid cancers worldwide. The mucosotropic genotypes infect the stratified epithelium of various locations, where persistent infection may lead to invasive carcinomas. While the causative role of HPV in certain anogenital and head and neck carcinomas is well established, the role of HPV in carcinomas arising in the mucosal membranes of the ocular adnexal tissue (the lacrimal drainage system and the conjunctiva) has been a topic of great uncertainty. Therefore, we conducted a series of studies to assess the correlation between HPV and carcinomas arising in the mucosa of the ocular adnexal tissue and characterize the clinical, histopathological, and genomic features of the tumors in the context of HPV status in a Danish nationwide cohort. We collected clinical and histopathological data and tumor specimens from patients with carcinomas of the conjunctiva and the lacrimal drainage system, and their potential precursors, identified in Danish nationwide registries. The HPV status of the tumors was determined by the combined use of HPV DNA polymerase chain reaction (PCR), HPV E6/E7 mRNA in-situ hybridization, and p16 immunohistochemistry. The genomic profile was investigated by high-throughput DNA sequencing targeting 523 cancer-relevant genes. The literature to date on carcinomas of the lacrimal drainage system and the conjunctiva was summarized. In the Danish cohort, 67% of all carcinomas of the lacrimal drainage system and 21% of all conjunctival carcinomas were HPV-positive. HPV16 was the most frequently implicated genotype. A full-thickness expression of the viral oncogenes E6 and E7 was evident in almost all HPV DNA-positive cases. The HPV-positive carcinomas of the conjunctiva and the lacrimal drainage system shared histopathological and genomic features distinct from their HPV-negative counterparts. The HPV-positive carcinomas were characterized by a non-keratinizing morphology, p16 overexpression, high transcriptional activity of HPV E6/E7, and frequent pathogenic variants in the PI3K-AKT signaling cascade. In contrast, the HPV-negative carcinomas were characterized by a keratinizing morphology, lack of p16 and E6/E7 expression, and frequent somatic pathogenic variants in TP53, CDKN2A, and RB1. Among the patients with conjunctival tumors, HPV positivity was associated with a younger age at diagnosis and a higher risk of recurrence. In conclusion, the results support an etiological role of HPV in a subset of conjunctival and LDS carcinomas and their precursor lesions. Our investigations have shown that the HPV-positive carcinomas of the ocular adnexa share genomic and phenotypic characteristics with HPV-positive carcinomas of other anatomical locations. Therefore, these patients may be eligible for inclusion in future basket trials and future treatment regimens tailored to the more frequently occurring HPV-positive carcinomas of other locations. Future research will further elucidate the diagnostic, prognostic, and predictive role of HPV in these carcinomas.

Tissue and circulating PD-L2: moving from health and immune-mediated diseases to head and neck oncology

Amongst the chief targets of immune-checkpoint inhibitors (ICIs), namely the Programmed cell death protein 1 (PD-1)/PD-Ligands (Ls) axis, most research has focused on PD-L1, while to date PD-L2 is still under-investigated. However, emerging data support PD-L2 relevant expression in malignancies of the head and neck area, mostly in head and neck squamous cell carcinoma (HNSCC) and salivary gland cancers (SGCs). In this context, ICIs have achieved highly heterogeneous outcomes, emphasizing an urgent need for the identification of predictive biomarkers. With the present review, we aimed at describing PD-L2 biological significance by focusing on its tissue expression, its binding to PD-1 and RGMb receptors, and its impact on physiological and anti-cancer immune response. Specifically, we reported PD-L2 expression rates and significant clinical correlates among different head and neck cancer histotypes. Finally, we described the biology of soluble PD-L2 form and its potential application as a prognostic and/or predictive circulating biomarker.

Advanced ocular surface squamous cell carcinoma (OSSC): long-term follow-up

PURPOSE

To analyze the clinical characteristics and long-term follow-up of patients with advanced ocular surface squamous cell carcinoma (OSSC) involving periocular tissues and/or orbit. Primary outcomes were overall survival (OS), disease-free survival (DFS), and overall recurrence rate (RR). Secondary outcomes were a correlation between primary outcomes and tumor location, American Joint Committee on Cancer Classification (AJCC) staging system, histological results, surgical margins, and type of treatment.

STUDY DESIGN

a retrospective case series.

METHODS

The medical records of patients affected by OSSC involving periocular tissues and/or orbit referring, from 01/2011 to 01/2020, to our tertiary referral center were reviewed.

RESULTS

Thirty-six eyes of 36 patients were included. The mean age was 68.2 years; 18 (50%) patients were males. The mean follow-up was 40 months. The RR was 64%. The OS at 12, 24, 36, and 60 months was respectively 97.1%, 92.7%, 92.7%, and 92.7%. The DFS at 12, 24, 36, and 60 months was respectively 62.9%, 50.8%, 41.6%, and 29.7%. Multicentric disease (p = 0.0039), inferior tarsus localization (p = 0.0428), histological diagnosis of high-risk SSCs (p = 0.0264), positive surgical margins (p = 0.0434), and excisional biopsy (EB) alone (p = 0.0005) were associated with an increased risk of recurrence. A shorter OS was observed in patients who underwent EB alone (p = 0.0049).

CONCLUSION

OSCC involving periocular tissues and/or orbit is an aggressive disease with a high recurrence rate. Multicentric disease, positive surgical margins, inferior tarsus localization, and surgery without adjuvant therapies are strong predictors of recurrence and are the main factors affecting prognosis.

PD-L1 and PD-L2 Expression Levels Are Low in Primary and Secondary Adenoid Cystic Carcinomas of the Orbit: Therapeutic Implications

PURPOSE

To determine if there is a biologic rationale for using checkpoint inhibitor drugs targeting programmed cell death ligand 1 (PD-L1) and PD-L2 in the treatment of adenoid cystic carcinoma of the orbit.

METHODS

Twenty-three cases of adenoid cystic carcinoma involving the orbit (13 primary lacrimal gland, 5 secondarily extending into the orbit, and 5 unspecified) were examined histopathologically. Immunohistochemistry for PD-L1, PD-L2, and CD8 was performed. Charts were reviewed for clinical correlations.

RESULTS

Expression of PD-L1 and of PD-L2 was overall low in adenoid cystic carcinoma (mean expression 1.4 ± 0.9 of 5 for PD-L1, mean 0.83 ± 1.1 of 5 for PD-L2), and tumor-infiltrating CD8-positive T-lymphocytes were sparse (mean 1.1 ± 0.51 of 3). Only 13 of the 23 (57%) cases expressed PD-L1 as a combined positive score ≥1 of cells. No associations were found between expression levels of these markers and patient sex, tumor site of origin, Tumor, Node, Metastasis stage, or patient outcome. A significant association was observed between stromal PD-L1 expression and tumor histopathologic subtype (p = 0.05), and between tumor PD-L1 expression and prior exposure to radiation (p = 0.03).

CONCLUSIONS

Checkpoint inhibitor drugs may have limited impact in the treatment and clinical course of orbital adenoid cystic carcinoma based on the low frequency of CD8 infiltrate and low expression of PD-L1 and PD-L2. Pretreatment with radiation, however, may improve tumor response to checkpoint inhibitor drugs.

High Expression of Programmed Death Ligand 1 and Programmed Death Ligand 2 in Ophthalmic Sebaceous Carcinoma: The Case for a Clinical Trial of Checkpoint Inhibitors

PURPOSE

To evaluate the expression of programmed death ligand 1 (PD-L1) and programmed death ligand 2 (PD-L2) in ocular adnexal sebaceous carcinoma (OASC), and to appraise these findings within the context of recent comparable studies.

DESIGNS

Retrospective case series.

METHODS

Twenty cases of primary OASC were immunostained for PD-L1, PD-L2 and CD8. PD-L1 and PD-L2 expression were graded with both the combined positive score (CPS) and the tumor proportion score (TPS). Both raw CPS and TPS were reported, as well as positivity with TPS and CPS ≥1. CD8 expression was graded on a 0-3 scale. Charts were reviewed for clinical correlations. The results of the current study were compared with results of similar recent investigations.

RESULTS

For the 20 cases, mean expression of PD-L1 with CPS was 29.7 (range 0-101.5) and with TPS was 12.2 (range 0-95.8); mean expression of PD-L2 with CPS was 7.9 (range 0-37.3) and with TPS was 1.9 (range 0-12.9). PD-L1 CPS ≥1 was detected in 95% of OASC, while PD-L1 TPS ≥1 was found in 75%. PD-L2 CPS ≥1 was present in 60%, while only 20% had PD-L2 TPS ≥1. Immune cells appeared to contribute to a substantial proportion of PD-L1 and PD-L2 positivity, and a conspicuous CD8-positive T-lymphocytic infiltrate was present in most tumors. Significant correlations were identified between tissue expression of PD-L1, PD-L2, and CD8. Tissues with greater levels of PD-L1 tended to express higher levels of PD-L2 and CD8. The degree of PD-L1 and PD-L2 expression was also associated with the area in millimeters squared of the immunostained tumor, suggesting that tumor sampling may influence interpretation of PD-L1 and PD-L2 expression in ocular adnexal tumors.

CONCLUSIONS

The current and preceding studies confirm that PD-L1 and PD-L2 are expressed in a high percentage of OASCs. These results support the premise that checkpoint inhibitor drugs hold considerable therapeutic promise for patients with OASC and stimulate the institution of clinical trials.

Intraductal sebaceous papilloma of a meibomian gland: a new entity possibly associated with the MSH6 subtype of the Muir-Torre syndrome

Over several months, a painless, multinodular, non-erythematous swelling of the deep tissues of his left upper eyelid developed in a 63-year-old man. An excisional biopsy with histopathologic evaluation disclosed a unique sebaceous papilloma within a cyst lined by non-keratinizing squamous epithelium that focally displayed a variably thick, superficial, eosinophilic cuticular layer. Immunohistochemical staining demonstrated that the tumor and its epithelial cystic lining had a profile consistent with Meibomian gland duct epithelium. Adipophilin highlighted cytoplasmic vacuolar lipid positivity. The encapsulation of the lesion, absence of nuclear atypia, and Ki-67 nuclear positivity restricted to the basilar cells established its intrinsically benign nature. The patient's clinical history was remarkable for pulmonary and colonic carcinomas resected, respectively, 20 years and 8 years earlier. DNA mismatch repair protein expression studies disclosed loss of nuclear immunostaining of MSH6 protein, pointing to the possibility of an underlying rare MSH6 variant of the Muir-Torre syndrome, not yet described in the ophthalmic literature. p16 nuclear positivity was also found in the tumor cells, indicating the possible role of high-risk human papillomavirus as an additional factor in the genesis of the tumor. Genetic evaluation of normal and tumoral tissues in future similar cases will detect if there is an underlying germline mutation versus a somatic mutation limited to the tumor. This will be required to fully establish a predictable linkage with this new subtype of the Muir-Torre syndrome.

Advances in Immunotherapy and Periocular Malignancy

Immunotherapy has significantly advanced the field of oncology in recent decades. Understanding normal immunosurveillance, as well as the ways in which tumor cells have evolved to evade it, has provided the knowledge for development of drugs that allow one's own immune system to target and destroy malignant cells (immunotherapy). Cutaneous malignancies are particularly sensitive to this class of drugs. In a very sensitive anatomic region such as the periocular tissue, where surgical excision may come with significant morbidity, this technology has had a strong impact in the successful treatment of historically challenging tumors.