Uveal Melanoma and Paraneoplastic Perivascular Dermal Melanocytic Proliferation in the Setting of Bilateral Diffuse Uveal Melanocytic Proliferation: The Potential Role of the Hepatocyte Growth Factor/c-Met Axis in Their Pathogenesis

Two patients, with non-small cell lung carcinoma treated with pembrolizumab, developed bilateral diffuse uveal melanocytic proliferation (BDUMP) with interesting histopathological features. The first patient developed a right ciliary body mass concurrently with BDUMP. The globe was enucleated. The ciliary body mass was a mitotically active epithelioid uveal melanoma, invading the trabecular meshwork and peripheral corneal stroma, with over 90% of the cells expressing Cyclin D1 protein. The melanoma showed no chromosome 3 or 8 changes. The background uvea showed diffuse, bland spindle cell melanocytic proliferation with much lower Cyclin D1 expression (around 10%). In the choroid, this population was punctuated by islands of pigmented epithelioid cells, some of which were necrotic. All these islands expressed a high level of Cyclin D1, and some islands expressed nuclear preferentially expressed antigen in melanoma (PRAME). The ciliary body mass, epithelioid cell islands, and the BDUMP all expressed c-Met (the receptor for hepatocyte growth factor [HGF]). The features were those of ciliary body melanoma and choroidal melanoma "tumorlets," developing on a background of BDUMP. The second patient developed bilateral periocular skin pigmentation following a diagnosis of BDUMP, which when biopsied, showed dermal islands of paraneoplastic perivascular melanocytic cell proliferation. These cells also expressed c-Met protein. These observations implicate the HGF/c-Met axis in the pathogenesis of BDUMP, the uveal melanomas in the ciliary body and choroid in the first patient and the paraneoplastic dermal melanocytic proliferation in the second patient.

Diagnosing Vitreoretinal Lymphomas-An Analysis of the Sensitivity of Existing Tools

Simple Summary

Diagnostics of vitreoretinal lymphoma is very challenging, as the possibility of receiving false negative results is common. We retrospectively analyzed the sensitivity of the most commonly used diagnostic methods including ancillary immunohistochemistry, Myeloid Differentiation Factor 88 (MyD88) L256P mutation analysis, polymerase chain reaction (PCR) for monoclonal rearrangements of immunoglobulin heavy chain (IgH) and T-cell Receptor (TCR) genes, flow cytometry, and IL10 and IL6 analysis, to diagnose vitreoretinal lymphomas from published data in the literature. MyD88 mutation analysis caused by a hotspot mutation in MyD88 was the most sensitive and had the lowest coefficient of variation.

Abstract

Vitreoretinal lymphoma (VRL) is a rare ocular pathology that is notorious for mimicking chronic uveitis, which is a seemingly benign condition in comparison. The most common form of VRL is the diffuse large B-cell type, and there has been a high mortality rate. This dismal prognosis can be improved significantly if the disease is diagnosed early, but until now there is no consensus on an appropriate diagnostic algorithm. We conducted a retrospective search of PubMed Central^® and analyzed results from thirty-three studies that were published between 2011–2021. The chosen studies incorporated some popular testing tools for VRL, and our analyses focused on comparing the average sensitivity of five diagnostic methods. The methods included cytology including ancillary immunohistochemistry, Myeloid Differentiation Factor 88 (MyD88) mutation analysis, polymerase chain reaction (PCR) for monoclonal rearrangements of immunoglobulin heavy chain (IgH) and T-cell Receptor (TCR) genes, flow cytometry, and IL10 and IL6 analysis. Across the varied diagnostic methods employed in thirty-three studies explored in this analysis, MyD88 mutation assay emerged as a strong contender given its sensitivity and low coefficient of variation. There is an imminent need for the introduction of newer assays that can further improve the sensitivity of identifying MyD88 mutation in cancer cells seen in the vitreous.

Ocular adnexal manifestations of neuroendocrine neoplasms: a case report and a major review

PURPOSE

To describe a patient with orbital neuroendocrine neoplasm (NEN)/carcinoid tumor and to review the clinical presentation, systemic work-up, histopathologic features, and outcome of all previously reported ocular adnexal (OA) NENs.

METHODS

A systematic literature review. PubMed/MEDLINE and Google Scholar databases were searched for all well-documented cases of OA NENs.

RESULTS

Final analysis yielded 94 patients with OA NENs, 50 females (53%) and 44 (47%) males with an average age of 63 years (range 14-86). Of 91 patients with known information, the most common presenting signs were proptosis (56/91, 61%) and visual disturbances (42/91, 47%), induced by a mass most commonly associated with an extraocular muscle (49/63, 78%). The majority of tumors (88/94, 94%) were metastases, most commonly from the gastrointestinal tract (52/88, 59%). OA NEN metastasis presented following detection of primary tumor in 73/94 (78%) patients (median time to metastasis 36 months, range 0-288 months) and as an initial manifestation of disease in 15/94 (16%) patients (median time to primary detection 18 months, range 1-108 months). Systemic work-up included extra-OA NEN biopsy (37/54, 69%), multimodal imaging (42/54, 78%), and other laboratory studies (32/54, 59%). Resection with or without adjuvant chemotherapy, radiotherapy, and biologics was the most common intervention for OA NENs (36/82, 44%). Of 67 patients with available follow-up, the median survival was 108 months (95% CI 55-161 months) and the absolute 5-year survival rate was 68%.

CONCLUSIONS

OA NENs are almost exclusively metastases and can precede detection of primary tumor by many months, requiring appropriate diagnostic work-up.

Primary Synovial Sarcoma of the Orbit: A Case Report and Update on Diagnostic Techniques

Synovial sarcoma is a malignant mesenchymal tumor that most commonly occurs in the deep soft tissue of the extremities in adolescents and young adults. Primary periocular synovial sarcoma is extremely rare with only 11 previously reported cases. We describe a 23-year-old woman who presented with a 1-year history of painful, progressive right upper eyelid swelling. She was subsequently found to have a superomedial orbital mass on CT scan. Pathologic evaluation revealed a spindle cell neoplasm with SS18 (SYT) rearrangement by fluorescence in situ hybridization studies, consistent with a monophasic synovial sarcoma. This case describes the clinical, radiographic, histopathologic, and molecular cytogenetic features of this rare orbital neoplasm, with an emphasis on the emerging diagnostic techniques and novel therapies.

Actinic Granuloma of the Conjunctiva: Case Series and Review of the Literature

PURPOSE

To characterize the clinical and histopathologic features of actinic granuloma of the conjunctiva.

DESIGN

Retrospective observational case series METHODS: Institutional pathology records between 2014 and 2020 were searched for all cases of conjunctival actinic granuloma. Information collected included age, sex, ocular and medical history, clinical findings, laboratory workup, treatment, follow-up, pathologic diagnosis, and histopathologic inflammation pattern.

RESULTS

Eight eyes of 8 patients, 5 men and 3 women, with a median age of 43 years (mean 49, range 24-83) were identified. Clinical diagnosis was pterygium (n = 4, 50%), inflamed pterygium (n = 1, 13%), pterygium vs conjunctival squamous cell carcinoma (n = 1, 13%), episcleritis vs inflamed pinguecula (n = 1, 13%), and scleritis vs keratoacanthoma (n = 1, 13%). Of 5 lesions with follow-up information, none recurred following excision with a median follow-up of 9 weeks (mean 19 weeks, range 1-61 weeks). Allergy/atopy was documented in 4 of 7 (57%) patients with available medical information. There were no other systemic associations. Histopathologically, actinic granuloma was associated with pterygium (n = 6, 75%) and pinguecula (n = 2, 25%). All lesions were composed predominantly of histiocytes and a variable number of foreign body-type giant cells associated with a focus of severe actinic elastosis. The inflammatory pattern was giant cell (n = 4, 50%), sarcoidal (n = 2, 25%), histiocytic (n = 1, 13%), and combined histiocytic and sarcoidal (n = 1, 13%).

CONCLUSION

Conjunctival actinic granuloma has diverse clinical and histopathologic manifestations, which need to be distinguished from other autoimmune, neoplastic, and infectious etiologies. This lesion frequently occurs in pre-existing pterygium and pinguecula and may be associated with allergy and atopy.

Preoperative Ultrasound-Guided Percutaneous Embolization of Orbital Lymphaticovenous Malformations Using Onyx

The treatment of orbital lymphaticovenous malformations (OLVMs) has evolved from simple surgical resection to a multimodal approach consisting of sclerosing agents, embolization, and resection depending on the specific components that compose the lesion. Here we present a representative case series of 5 nonconsecutive patients who underwent percutaneous embolization of OLVMs with the Onyx Liquid Embolic System (Medtronic, Dublin, Ireland) before surgical resection between 2019 and 2021. OLVMs are rare, benign, congenital lesions that grow with age and can become symptomatic and disabling. Treatment can be conservative or invasive; depending on the clinical presentation and characteristics of the lesions, treatment modalities can vary. Preoperative percutaneous embolization of OLVMs with the Onyx system is a promising technique, as demonstrated in this case series.

Overlapping Immunohistochemical Features of Adenocarcinoma of the Nonpigmented Ciliary Body Epithelium and Renal Cell Carcinoma

PURPOSE

To find immunohistochemical markers that distinguish adenocarcinoma of the nonpigmented ciliary epithelium (NPCE) from metastatic carcinoma, especially metastatic renal cell carcinoma.

DESIGN

Retrospective case series.

METHODS

Three cases of adenocarcinoma of the NPCE were examined histologically with hematoxylin-eosin stain and immunohistochemical stains including vimentin, AE1/AE3, Cam 5.2, CK7, PAX2, PAX8, AMACR, and CAIX. We also reviewed previously reported cases of this tumor.

RESULTS

We found that the immunohistochemical profile of adenocarcinoma of the NPCE can overlap with renal cell carcinoma. Both tumors can express vimentin, cytokeratin AE1/AE3, Cam 5.2, PAX2, PAX8, and AMACR. One of the adenocarcinomas of the NPCE in our series also expressed CD10 and the renal cell carcinoma marker (RCC Ma). Carbonic anhydrase IX (CAIX) was not detected in any of the 3 tumors.

CONCLUSIONS

Adenocarcinomas arising in phthisic eyes can be diagnostically challenging. We have found it particularly difficult to distinguish adenocarcinoma of the NPCE from metastatic carcinoma, especially metastatic clear cell renal cell carcinoma and papillary renal cell carcinoma. Because of the immunophenotypic overlap, most patients will require systemic workup including imaging of the kidneys to be certain of the diagnosis.

PAX8 Expression in the Crystalline Lens and Lens-Derived Lesions

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Orbital and Ocular Adnexal Manifestations of Adult T-Cell Leukemia/Lymphoma: a Case Report and Systematic Review

PURPOSE

To describe a patient with orbital adult T-cell leukemia/lymphoma (ATLL) and to review the literature on presentation, diagnostics, management, and clinical course of this rare disease.

METHODS

A systematic literature review. PubMed/MEDLINE and Google Scholar databases were searched for all well-documented cases of orbital/ocular adnexal ATLL.

RESULTS

Sixteen patients were included in the final analysis. The median age at diagnosis was 47 years (range, 20-85), 9/16 patients (56%) were male, and patients were of Japanese (10/16, 63%), Caribbean (5/16, 31%), or African (1/16, 6%) origin. Proptosis (6/15, 40%) and visual loss (5/15, 33%) were the most common presenting signs. Involvement of adjacent structures was documented in 8 of 16 (50%) patients. All patients had evidence of systemic ATLL, which was identified concurrently with orbital/ocular adnexal disease in 9 of 15 (60%) patients. Management included multi-agent chemotherapy with steroids (9/13, 69%), antivirals (2/13, 15%), biologic agents (4/13, 31%), and umbilical cord blood transplantation (1/13, 8%). Most patients (8/12, 67%) experienced at least partial remission with disease relapse occurring in 6 of 8 patients (75%). The median survival time was 28 months (95% CI, 5.5-50.5 months).

CONCLUSIONS

Adult T-cell leukemia/lymphoma should be considered in the differential diagnosis of orbital and ocular adnexal space-occupying lesions, particularly in male patients from endemic regions. Orbital disease is frequently locally aggressive and presents concurrently with systemic ATLL, highlighting the importance of comprehensive multimodal work-up and multidisciplinary management. Emerging targeted therapies and hematopoietic stem cell transplant may prolong survival.

Immunohistochemical Profiling of Conjunctival Melanocytic Intraepithelial Lesions, Including SOX10, HMB45, Ki67, and P16

PURPOSE

To determine the usefulness of melan-A, SOX10, HMB45, and p16 immunohistochemical stains in the distinction between the low-grade and high-grade conjunctival melanocytic intraepithelial lesions, either independently or as components of an immunohistochemical panel.

DESIGN

Retrospective observational case series.

METHODS

Institutional pathology records between 2014 and 2018 were searched for all patients with conjunctival melanocytic intraepithelial lesions. Biopsies without supporting clinical history or tissue available for review and immunohistochemical analysis were excluded. Clinical, histopathologic, and immunohistochemical (p16, SOX10, HMB45, and Ki-67) findings were recorded.

RESULTS

Thirty-one patients underwent 47 biopsies for conjunctival melanocytic lesions between 2014 and 2018. Pathologic diagnoses were low-grade conjunctival melanocytic intraepithelial lesion (n = 18, 38%) and high-grade conjunctival melanocytic intraepithelial lesion/melanoma in situ (n = 29, 62%). The addition of melan-A and SOX10 immunohistochemical stains resulted in an upgrade of conjunctival melanocytic intraepithelial lesion from low-grade to high-grade in 2 (4%) of 47 cases. The addition of melan-A and SOX10 immunohistochemical stains did not downgrade any of the histomorphologically high-grade lesions. In a clinical-pathologic multivariable model, the parameters most predictive of high-grade melanocytic intraepithelial lesion/melanoma in situ were involvement of the caruncle (odds ratio [OR] = 19, confidence interval [CI] 1.6-212; P = .02] and p16 cytoplasmic H-score >30 (OR = 81, CI 2.7 to >999; P = .01) CONCLUSION: Although the stains for melanocytic markers melan-A and SOX10 facilitate assessment of melanocytic intraepithelial lesions, the current immunohistochemical panels have limited value in distinction between the low-grade and high-grade intraepithelial melanocytic proliferations and need to be used judiciously.

Imaging of Macrophage-Like Cells in Living Human Retina Using Clinical OCT

Purpose

To image retinal macrophages at the vitreoretinal interface in the living human retina using a clinical optical coherence tomography (OCT) device.

Methods

Eighteen healthy controls and three patients with retinopathies were imaged using a clinical spectral-domain OCT. In controls, 10 sequential scans were collected at three different locations: (1) ∼9 degrees temporal to the fovea, (2) the macula, and (3) the optic nerve head (ONH). Intervisit repeatability was evaluated by imaging the temporal retina twice on the same day and 3 days later. Only 10 scans at the temporal retina were obtained from each patient. A 3-µm OCT reflectance (OCT-R) slab located above the inner limiting membrane (ILM) surface was averaged.

Results

In controls, ramified macrophage-like cells with regular spatial separation were visualized in the temporal and ONH OCT-R images; however, cell structures were not resolvable at the macula. Interim changes in cell position suggestive of cell translocation were observed between images collected on the same day and those collected 3 days later. There was considerable variation in cell density and nearest-neighbor distance (NND) across controls. Mean ± SD cell densities measured at the temporal and ONH were 78 ± 23 cells/mm² and 57 ± 16 cells/mm², respectively. Similarly, mean ± SD NNDs measured at the temporal and ONH were 74.3 ± 13.3 µm and 93.3 ± 20.0 µm, respectively. Nonuniform spatial distribution and altered morphology of the cells were identified in patients with retinopathies.

Conclusions

Our findings showed regular spatial separation and ramified morphology of macrophage-like cells on the ILM surface with cell translocation over time in controls. Their distribution and morphology suggest an origin of macrophage-like cells such as microglia or hyalocytes.

Gene Fusions in Ocular Adnexal Tumors

PURPOSE

To highlight the increasing importance of gene fusions in the diagnosis, prognosis, and therapy of ocular adnexal tumors.

DESIGN

Perspective.

METHODS

A focused review of gene fusions, their pathogenic mechanism, and gene fusion detection methods in lacrimal gland and primary orbital and ocular adnexal soft tissue tumors; reappraisal of diagnostic, prognostic, and therapeutic approach to ocular adnexal tumors in light of emerging molecular genetic data.

RESULTS

The widespread implementation of fluorescence in situ hybridization and next-generation sequencing methods in pathology practice has led to identification of recurrent gene rearrangements and fusions in a variety of tumors. As a result, molecular genetic methods have become the gold standard for diagnosis of tumors with overlapping histology and immunophenotype, such as small round blue cell tumors. Identification of canonic gene fusions has led to development of sensitive and specific immunohistochemical markers, such as STAT6 in solitary fibrous tumor. In addition to diagnostic accuracy, gene fusions have prognostic implications, such as unfavorable prognosis of PAX3-FOXO1 fusion in alveolar rhabdomyosarcoma. Finally, recognition of gene fusions as a driving mechanism in neoplasia has led to development of U.S. Food and Drug Administration-approved targeted therapies, such as TRK inhibitors for NTRK fusion-positive cancers.

CONCLUSION

The discovery of recurrent gene fusions in various tumors, including those involving ocular adnexa, has led to a deeper insight into the molecular mechanisms of these neoplasms, revolutionizing our approach to their diagnosis, prognostication, and therapy.

Ocular adnexal lymphoma: A single-institution retrospective study

PURPOSE:

To characterize demographic, clinical, and histopathologic features of ocular adnexal lymphoma (OAL) at a single institution.

METHODS:

Retrospective review of all patients with pathologic diagnosis of OAL between 2015 and 2020.

RESULTS:

There were 133 patients with OAL, with a median age of 65 years (range 23–97) and a slight female predominance (male: female = 1:1.46), (n = 79, 59%). The majority of tumors were non-Hodgkin B-cell lymphomas (n = 131, 99%), most frequently Extranodal Marginal Zone B-Cell Lymphoma (EMZL, n = 93, 70%), followed by follicular lymphoma (n = 21, 16%), chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 7, 5%), diffuse large B-cell lymphoma (n = 5, 4%), and mantle cell lymphoma (n = 5, 4%). The most frequently involved sites included the orbit (n = 85, 64%) and conjunctiva (n = 43, 32%). Information was available on oncologic staging in 78 (59%), treatment in 82 (62%), and follow-up in 75 (56%) patients. By the Ann-Arbor classification system, patients were classified as IE (54/78, 69%), IIE (9/78, 12%), IIIE (6/78, 8%), and IVE (9/78, 12%). The most common treatments included external beam radiotherapy (standard and ultra-low-dose) (48/82, 59%), biologics (22/82, 27%), and surgical excision with cryotherapy (14/82, 17%) (some patients had >1 therapy). Median follow-up time was 24 months (range 0–221 months). Recurrence was observed in 13% (10/75) with a median time to recurrence of 60 months (95% confidence interval 47–73 months). Excision with cryotherapy as a sole treatment modality was associated with earlier recurrence (P = 0.003).

CONCLUSION:

In this largest single-center study of OAL, we found that most OAL were Ann-Arbor Stage IE EMZL, occurring in older patients with a female predominance. Early recurrence was noted in tumors treated with excision and cryotherapy alone.

Ocular adnexal metastases from renal cell carcinoma: An update and comprehensive literature review

PURPOSE:

The purpose of this study was to review the clinical presentation, systemic work-up, and outcomes of all previously reported ocular adnexal (OA) metastases from renal cell carcinoma (RCC).

METHODS:

This was a literature review. PubMed and Google Scholar databases were searched for all well-documented cases of OA metastases from RCC.

RESULTS:

Final analysis identified 44 patients with either biopsy-confirmed (41/44, 93%) or treatment response-documented (3/44, 6%) OA metastases from RCC. Thirty-four (77%) patients were male. The median age was 60 years (mean: 60, range: 22–87 years). The most common presenting signs were proptosis (19/44, 43%) and OA mass (14/44, 32%). Metastases most frequently involved the orbital bones (10/44, 23%) and adjacent extraconal fat, extending from the sinonasal tract in 7/10 (70%) of these cases. OA metastases were initial manifestation of RCC in 18/44 (41%) patients. At the time of primary tumor diagnosis, 22 of 30 (73%) patients had American Joint Committee on Cancer Stage IV disease with metastases to 2 or more sites in 13 (57%) patients. Seventeen of 42 (40%) patients underwent local therapy only, which most commonly included excision/exenteration with margin control (10/17, 59%). Twenty-five of 42 (60%) patients had systemic therapy, which included biologic agents and chemotherapy. The absolute 5-year survival rate was 66% with significantly improved survival in patients reported after 2006 (92% vs. 42%, P = 0.04) and in those with isolated OA metastases (100% vs. 27%, P = 0.02) at 30 months.

CONCLUSION:

Although RCC metastases to OA occur in a setting of advanced disease, the recent advances in diagnostic modalities and targeted therapies resulted in improved survival.

Usefulness of PAX8 Immunohistochemistry in Adult Intraocular Tumor Diagnosis

PURPOSE

To evaluate the distribution of the PAX8 transcription factor protein in ocular tissues and to investigate if immunohistochemical stains for this biomarker are useful in the diagnosis of intraocular tumors.

DESIGN

Observational case series.

PARTICIPANTS

Excision and cytologic analysis specimens of 6 ciliary body epithelial neoplasms, 2 iris epithelial neoplasms, 3 retinal pigment epithelial neoplasms, 3 intraocular medulloepitheliomas, 15 uveal melanomas, and 5 uveal melanocytomas.

METHODS

Hematoxylin-eosin and PAX8 immunohistochemical stains were performed on all specimens. In appropriate cases, bleached preparations and other immunohistochemical stains, including AE1/AE3 cytokeratin, Lin28A, and CD45, were performed.

MAIN OUTCOME MEASURES

Distribution of PAX8 expression in normal and neoplastic tissue.

RESULTS

Strong nuclear PAX8 expression was observed in the normal corneal epithelium, iris sphincter pupillae muscle, iris pigment epithelium and dilator muscle complex, nonpigmented and pigmented epithelia of the ciliary body, lens epithelium, and a subset of retinal neurons. The normal retinal pigment epithelium and uveal melanocytes did not stain for PAX8. The ciliary body epithelial and neuroepithelial tumors (adenoma, adenocarcinoma, and medulloepithelioma) showed uniform strong nuclear PAX8 immunoreactivity. All melanocytic tumors (iris melanoma, ciliary-choroidal melanoma, and melanocytoma) and retinal pigment epithelial neoplasms showed negative results for PAX8. A subset of tumor-associated lymphocytes, most prominent in uveal melanoma, showed positive results for PAX8. The uniformity of the PAX8 staining was superior to the variable cytokeratin staining in the ciliary epithelial neoplasms and the variable Lin28A staining in malignant medulloepithelioma. The veracity of PAX8 staining was equally as robust on cytologic analysis and open-flap biopsy specimens of ciliary epithelial and iris epithelial neoplasms, melanocytoma, and melanoma.

CONCLUSIONS

PAX8 has proven to be a very useful diagnostic marker in a select group of adult intraocular tumors, and we highly recommend its inclusion in diagnostic antibody panels of morphologically challenging intraocular neoplasms.

Lacrimal Gland Hamartoma (Formerly Termed Dacryoadenoma)

PURPOSE

Since the original description of "dacryadenoma" by Jakobiec and associates, the data on this unusual epibulbar lacrimal gland lesion remain sparse. The aim of this study was to characterize clinically, morphologically, and immunohistochemically this isolated epibulbar lacrimal gland lesion.

DESIGN

Retrospective observational case series.

METHODS

Institutional pathology records between 2000 and 2019 were searched for all cases of isolated epibulbar lacrimal gland lesions. Tissue from 3 normal lacrimal glands and 1 complex choristoma were included for comparative analysis. Clinical, histopathologic, and immunohistochemical findings were recorded.

RESULTS

Four patients with isolated epibulbar lacrimal gland lesions, 2 male and 2 female, with a median age of 18 years (range, 12-57) were identified. All patients presented with recent onset of unilateral pink-to-orange, well-circumscribed subepithelial juxtaforniceal (3/4, 75%), or nasal (1/4, 25%) bulbar conjunctival nodules, which were asymptomatic (3/4, 75%) or associated with foreign body sensation (1/4, 25%). When compared with the normal lacrimal gland and complex choristoma, all isolated epibulbar lacrimal gland lesions were composed predominantly of variably dilated, branching tubular structures with pseudo-apocrine snouts, and either totally absent (2/2, 50%) or rare (2/2, 50%) ducts and rare acinar zymogen granules (3/4, 75%).

CONCLUSION

Our study confirms that a subset of isolated epibulbar lacrimal gland lesions differs morphologically and immunohistochemically from normal lacrimal gland tissue and the lacrimal gland in a complex choristoma. These differences range from subtle to overt, suggesting that isolated epibulbar lacrimal gland lesions may have originated from precursor cellular elements indigenous to the conjunctiva (hamartia) and grew into disorganized lacrimal gland tissue.

Lacrimal drainage apparatus melanoma remotely following treatment and resolution of conjunctival melanoma

Lacrimal drainage apparatus melanoma is a rare entity that may arise primarily or, more commonly, as secondary involvement from melanoma originating elsewhere. Conjunctival melanoma may involve the lacrimal drainage apparatus (LDA) via spread along the canalicular epithelium, separate in situ processes, or direct invasion. Only seven cases exist in the literature where conjunctival melanoma remotely recurred in the LDA. We report three additional patients, two with invasive conjunctival melanoma and one with primary acquired melanosis (PAM) with severe atypia/melanoma in situ, who developed LDA melanoma at 5, 8, and 16 years after initial treatment of conjunctival melanoma. This report confirms the ability of conjunctival melanoma to give rise to spatially and temporally remote LDA melanoma despite adequate local treatment, and reviews the proposed mechanisms and associated characteristics of LDA recurrence in conjunctival melanoma.

Conjunctival nevi and melanoma: multiparametric immunohistochemical analysis, including p16, SOX10, HMB45, and Ki-67

The role of p16 in the diagnosis and prognosis of conjunctival melanocytic lesions in the context of other clinical and immunohistochemical parameters has not been systematically explored. This study was conducted to determine whether p16 is a useful parameter in the diagnosis and prognosis of conjunctival melanocytic nevi and melanoma, either independently or as a component of immunohistochemical panels. Sixty-one patients underwent 61 biopsies for conjunctival melanocytic lesions between 2014 and 2018. Pathologic diagnoses were melanoma (n = 25, 41%), nevus (n = 21, 34%), and conjunctival melanocytic lesion of uncertain malignant potential (n = 15, 25%). The biopsies were assessed for expression of p16, SOX10, HMB45, and Ki-67. In a multivariable model, the parameters most predictive of melanoma versus nevus were diffuse HMB45 staining (odds ratio [OR] = 45, confidence interval [CI] = 4.4-457, P = .02] and p16 nuclear H-score≤115 (OR = 9.5, CI = 1.2-77; P = .04). There was no association of p16 expression with melanoma thickness. Next-generation sequencing identified no CDKN2A mutations or copy number alterations in 12 conjunctival melanomas, including the tumors with absent p16 expression. This study demonstrates that p16 immunohistochemical stain is useful in distinguishing conjunctival melanocytic nevi from melanoma, particularly in combination with HMB45. P16 expression does not appear to correlate with CDKN2A status and melanoma thickness.