Lipomatous Change in Uveal Melanoma: Histopathological, Immunohistochemical and Cytogenetic Analysis

Abstract

Purpose: The aim of this study was to describe a case of lipomatous change in uveal melanoma. Procedures: The patient presented with a 2-year history of blurry vision. A full examination of the right eye revealed a dome-shaped pigmented subretinal mass in the choroid with a thickness of 9 mm and a diameter of 15 mm. The eye was enucleated and prepared for histopathologic, genetic and molecular investigation. Results: Histopathology revealed a small circumscribed area consisting of mature adipocytic appearing cells with abundant clear cytoplasm and small peripheral flattened nuclei within a spindle-cell melanoma of the uvea. The cytoplasm of the adipocytic cells stained negative for periodic acid-Schiff and Alcian blue and positive for Melan-A, HMB-45 and tyrosinase, confirming melanocytic lineage. Fluorescence in situ hybridization analysis confirmed trisomy of chromosome 6p22 and disomy of chromosome 3p13 in the nuclei of both the tumor spindle type B cells and in the nuclei of lipomatous tumor cells. Conclusions: Lipomatous change can be added to the many histopathologic faces of uveal melanoma. To our knowledge, this is the first report of lipomatous change in uveal melanoma performed with cytogenetic investigations.

Uveal melanoma: Towards a molecular understanding

“…B) Hematoxylin-eosin (HE) staining shows that the tumor consists of spindletype UM cells and several adipocytic appearing cells (100x). Reproduced with permission from Yavuzyigitoglu et al (2016a), via Copyright Clearance Center. (Yavuzyigitoglu et al, 2016b).…”

“…Several clinical and histological features can predict high metastatic risk, such as large tumor size, extraocular extension, high mitotic activity and an epithelioid cell type, whereas the spindle cell type is associated with low metastatic risk (Fig. 1) (McLean et al, 1982;Shields et al, 2009;Yavuzyigitoglu et al, 2016a). Genetic features associated with metastatic disease include loss of chromosome 3 and mutations in the BAP1 and SF3B1 gene.…”

Choroidal and Sub-Retinal Pigment Epithelium Caverns

“…20 Because of their small size, high apparent lipid content, and absence of cells, internal septa, and capsules, globules can be differentiated from lipomatous tumors, a heterogeneous group of benign and malignant soft tissue masses. 21,22 There was no evidence of prior hemorrhage leading to extracellular cholesterol deposition, as occurs in atheroma. 23 Like Friedman, we observed an absence of cell-mediated inflammation in the stroma surrounding globules.…”

Lipid-Producing Ciliochoroidal Melanoma with Expression of HMG-CoA Reductase

“…Van Ly/Wang/Conway/Giblin/Liang/ Lukeis/Lim/Hesson/Cherepanoff Ocul Oncol Pathol 2020;6:416-421 420 DOI: 10.1159/000510393 [13], and high expression may be a prognostic factor associated with more advanced disease [14]. Recently, lipid production has also been demonstrated in a subset of UM, but the drivers of this lipidic profile remain unclear [5,6]. The current report describes expression of HMG-CoA reductase in a lipid-producing UM with high-risk molecular cytogenetic (combined monosomy3 and high level 8q gain) [15,16] and mutational signatures.…”

“…Lipid synthesis and metabolism are known to play an important role in tumour survival in cancer cell biology [4]. Lipid production in UM has received relatively little research attention [5,6]. In this report, we aim to add to this body of knowledge by describing the clinical, histological, immunohistochemical, molecular, and cytogenetic findings in a lipid-producing ciliochoroidal melanoma with a high metastatic risk.…”