Eyelid Myxoma in Carney Complex: Prevalence, Histo-pathology & Genetics

Abstract

Abstract: : Purpose: Carney complex (CNC) is a rare disorder inherited in an autosomal dominant manner and associated with spotty cutaneous and mucosal pigmentation, myxomas and endocrine overactivity; in half of the patients, mutations of the PRKAR1A gene, a protein kinase A regulator, have been identified. In the present investigation, we studied the prevalence of eyelid myxomas in patients with CNC; in addition, eyelid tumors from one patient were subjected to histopathologic and genetic studies after microdissection. Methods:The National Institutes of Health/Mayo Clinic registry of more than 380 patients with CNC was searched for eyelid myxomas. Two large nodular lesions that were identified in the right upper eyelid of a 27-year-old with CNC, were excised and processed for routine histology and immune histochemistry against vimentin. Cells from the tumor, the normal stroma and the epithelium were microdissected. DNA was extracted and analyzed of the PRKAR1A gene. Results: Cutaneous and/or mucosal myxomas are present in 33% of the CNC patients. The eyelid is the second most common site, after simple, superficial cutaneous myxomas that are seen mostly on the trunk, the face, and the gluteal region of the lower extremities. Nipple myxomas are the third most common such tumors. Histological analysis of the excised tumors revealed a myxomatous area with mucinoid and fibrous elements as well as areas with hypertrophy of sebaceous glands. The myxomatous areas stained positively with vimentin. DNA analysis showed that the patient was a heterozygote for the 578delTG PRKAR1A inactivating mutation. When the DNA isolated from different phenotypic tumors was compared there was loss of heterozygosity (LOH). Conclusions:Eyelid myxomas are a frequent manifestation of CNC, a multiple tumor syndrome associated with an increased risk for certain malignancies and endocrine dysfunction. Patients with eyelid myxomas, especially when those are multiple and/or recurring, may need to be screened for this genetic condition. In at least one case, LOH was not present within the tumor, suggesting that PRKAR1A haploinsufficiency may be sufficient for tumorigenesis in the eyelid.

Keywords: eyelid • tumors