Sarah Alghamdi

Apocrine adenocarcinoma of the eyelid

The Henry C. Witelson Ocular Pathology Laboratory, McGill University, 1001 Boul Decarie, Montreal H4A 3J1, Canada 2Department of Ophthalmology, King Saud University, PO Box 245, Riyadh 11411, Saudi Arabia 3Department of Ophthalmology, McGill University, 5252 Boul de Maisonneuve ouest, Montreal H4A 3S5, Canada Correspondence to: Pablo Zoroquiain. The Henry C. Witelson Ocular Pathology Laboratory, McGill University, 1001 Boul Decarie, Montreal H4A 3J1, Canada. zoroquiain@gmail.com Received: 2015-06-14 Accepted: 2016-03-07

Eyelid Mycetoma Masquerading as Sebaceous Carcinoma.

A 56-year-old Asian woman presented with an upper eyelid mass. The lesion was exposed after eversion of the eyelid revealing a thickened tarsus with yellowish areas. Working diagnosis was sebaceous carcinoma. Biopsy was performed. Histopathological studies showed a mycotic eumycetoma with Splendore-Hoeppli phenomena and - microbiologic cultures grew Scedosporium apiospermum. The patient was started on voriconazole 200 mg po bid with adequate serum levels. A complete response was observed after 18 weeks of voriconazole therapy. To the best of our knowledge, this is the first published case of S. apiospermum eumycotic mycetoma of the eyelid. It is important to consider mycotic infection in the differential diagnosis of eyelid tumors even in healthy patients.

Melanocytoma-like melanoma may be the missing link between benign and malignant uveal melanocytic lesions in humans and dogs: a comparative study.

The cutoff presented in the current classification of canine melanocytic lesions by Wilcock and Pfeiffer is based on the clinical outcome rather than morphological concepts. Classification of tumors based on morphology or molecular signatures is the key to identifying new therapies or prognostic factors. Therefore, the aim of this study was to analyze morphological findings in canine melanocytic lesions based on classic malignant morphologic principles of neoplasia and to compare these features with human uveal melanoma (HUM) samples. In total, 64 canine and 111 human morphologically malignant melanocytic lesions were classified into two groups (melanocytoma-like or classic melanoma) based on the presence or absence of M cells, respectively. Histopathological characteristics were compared between the two groups using the &khgr;2-test, t-test, and multivariate discriminant analysis. Among the 64 canine tumors, 28 (43.7%) were classic and 36 (56.3%) were melanocytoma-like melanomas. Smaller tumor size, a higher degree of pigmentation, and lower mitotic activity distinguished melanocytoma-like from classic tumors with an accuracy of 100% for melanocytoma-like lesions. From the human series, only one case showed melanocytoma-like features and had a low risk for metastasis characteristics. Canine uveal melanoma showed a morphological spectrum with features similar to the HUM counterpart (classic melanoma) and overlapped features between uveal melanoma and melanocytoma (melanocytoma-like melanoma). Recognition that the subgroup of melanocytoma-like melanoma may represent the missing link between benign and malignant lesions could help explain the progression of uveal melanoma in dogs; these findings can potentially be translated to HUM.

Traumatic iridial extrusion mimicking a conjunctival melanocytic neoplasm.

Conjunctival melanoma is a rare malignant tumour of the eye. Its diagnosis represents a challenge for general pathologists due to low exposure to ocular biopsies and a broad differential diagnosis. In addition, conjunctival samples are often small and are associated with a high frequency of artefacts due to their processing. Here, we present the first case to date of a traumatic iridial extrusion masquerading as a conjunctival melanocytic neoplasm. An 83-year-old Asian man presented with a conjunctival-pigmented nodule surrounded by an area of diffuse pigmentation. Histopathology revealed in the nodule a well-demarcated lesion composed of spindle shaped melanocytes with thick-walled blood vessels. At higher magnification, the blood vessels were composed of thick walls with collagen fibres in an onion-skin-like arrangement. The histological findings were consistent with extruded iridial tissue. The map biopsies of the flat, pigmented lesion showed melanocytic cell proliferation with dendritic processes restricted to the lamina propria without any epithelial involvement, consistent with ocular melanocytosis. The diagnosis of conjunctival melanocytic lesions is challenging, and non-neoplastic conditions should always be included in the differential diagnosis. Pathologists should correlate clinicopathological findings and be familiar with the normal histology in order to achieve the correct diagnosis.

Conjunctival Involvement of T-Cell Lymphoma in a Patient with Mycosis Fungoides.

Background. Ocular involvement in mycosis fungoides (MF) cases occurs in one-third of patients with the eyelid being the most frequent site affected; however, conjunctival involvement is rarely reported. Herein, we report a rare case of conjunctival involvement of MF. Case Presentation. A 66-year-old man who was previously diagnosed with MF in 2010 and was treated presented in 2014 complaining of foreign body sensation and redness in both eyes. Slit lamp examination of both eyes showed erythematous conjunctival growth that extended circumferentially. Physical examination revealed erythematous skin lesions on different body parts. Conjunctival biopsy was performed and revealed a dense, highly polymorphic lymphocytic population. The immunophenotype demonstrated a neoplastic T-cell origin consistent with MF. A diagnosis of conjunctival involvement by MF was made. The conjunctiva was treated with radiotherapy resulting in tumor regression. There were no recurrences at the 6-month follow-up. Conclusion. T-cell lymphoma should be considered in patients with a history of MF presenting with conjunctival and skin lesions.

Gonadotropin-Releasing Hormone Receptor is expressed in Retinoblastoma

Background: Despite the fact that retinoblastoma treatment has dramatically increased the survival and vision preservation in these patients, it is still important to pursue new therapeutic targets to minimize the side-effects of current therapies. Gonadotropin releasing hormone (GnRH) has been shown to exert a direct anti-proliferative effect on many types of malignancies, such as breast cancer, skin melanoma, and glioblastoma. The aim of this study is to describe the presence of GnRH receptor (GnRHR) in retinoblastoma in order to identify a possible new therapeutic target for this disease. Methods: Protein expression of GnRHR was studied by immunohistochemistry in 32 eyes with retinoblastoma and in the Y79 retinoblastoma cell line. Expression was scored according to intensity (1-3) and distribution (1-4), which were multiplied to generate an immunoreactive score (IRS). A score of 1 to 6 was considered low, while scores higher than 6 were considered high. The Fisher’s exact test was used to compare GnRHR IRS with presence or absence of each morphological high-risk feature. Results: GnRHR was expressed in all retinoblastoma cases and in the Y79 cell line. High, and low expression according to IRS score was evident in 62.5% and 37.5% of cases. There were no differences in GnRH IRS with respect to uni- versus multi-focal tumors, type of growth (mixed/endophytic), rosette formation, choroidal invasion, extraocular extension orextension to the sclera, or optic nerve invasion. Conclusion: GnRHR is expressed in varying degrees in all retinoblastomas. Therefore, GnRHR may be a novel therapeutic target for the treatment of retinoblastoma. Moreover, GnRHR expression could be a biomarker for the responders. Nevertheless, GnRHR expression did not correlate with morphological prognostic factors in this series. Further studies with a larger number of cases and follow up are needed to confirm our results.

Diagnostic value of SOX-10 immunohistochemical staining for the detection of uveal melanoma.

Objectives SOX-10 has been shown to be a sensitive marker of cutaneous melanoma. This study aimed to evaluate Sox-10 expression in uveal melanoma. Methods A total of 40 tissue blocks of enucleated eyes with uveal melanoma were cut and stained using an anti-SOX-10 mouse monoclonal antibody and HMB-45 antibody. Results SOX-10 showed exclusive nuclear positivity in 100% of the uveal melanoma cases (38/38). HMB-45 showed cytoplasmic positivity in 97.3 (37/38). Positivity for SOX-10 was also noted in the inner and outer nuclear layers of the retina in 78% of the enucleated eyes. Conclusions SOX-10 expression proved to be the most sensitive marker for uveal melanoma, and therefore, we propose a modified panel for the diagnosis of uveal melanoma that includes both SOX-10 and HMB-45. The observation of distinct, diffuse nuclear SOX-10 expression in retinal inner and outer nuclear layers is a finding that warrants further investigation as a marker for retinoblastoma.