18F-FDG PET-CT for Staging of Conjunctival Melanoma
A 34-year-old male patient was referred to our hospital with a six-month history of a progressive pigmented nodule in the palpebral conjunctiva of the left eye. The patient reported a previous pigmented lesion detected years before. Full ophthalmologic examination revealed a pigmented lesion encompassing both palpebral margins of the left eye, in the bulbar and palpebral conjunctiva. A firm, preauricular node was detected by physical examination. No conjunctival pigmented lesion was detected in the right eye. Systemic examination was unremarkable.\nMagnetic resonance imaging (MRI) revealed thickening of the conjunctiva, with a heterogeneous signal at T1 and short time inversion - recovery (STIR), and positive enhancement with gadolinium. The lesion involved the anterior portion of the ocular globe. There was no evidence of metastatic disease.\nConjunctival biopsy showed atypical melanocytosis, compatible with malignant melanoma in situ of the conjunctiva, with 2 mm of intraepithelial extension.\nCT with intravenous contrast revealed two nodules at the superior lobe of the left lung and one nodule at the inferior lobe of the left lung. A fine needle aspiration biopsy of the preauricular lymph node was positive for malignancy.\nTo restage the patient for planning of treatment, a PET-CT scan with 18F-FDG was performed. This study revealed increased tracer uptake at the primary ocular lesion [] and at the preauricular node []. The scan was negative for systemic spread of the disease.