|
|
 |
|
|
|
|
|
A 66-year-old woman with extensive conjunctival melanosis
Digital Journal of Ophthalmology 2014
Volume 20, Number 2
May 8, 2014
DOI: 10.5693/djo.03.2013.12.002
|
Printer Friendly
|
|
|
Helen Merritt, MD | Orbital Oncology & Ophthalmic Plastic Surgery Program, Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas; Ruiz Department of Ophthalmology and Visual Science, The University of Texas Medical School at Houston Mathieu Bakhoum, PhD | Orbital Oncology & Ophthalmic Plastic Surgery Program, Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas; University of Texas Medical Branch, Galveston, Texas Matthew Sniegowski, MD | Orbital Oncology & Ophthalmic Plastic Surgery Program, Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas Bita Esmaeli, MD | Orbital Oncology & Ophthalmic Plastic Surgery Program, Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas
|
|
|
| Diagnosis and Discussion | Surgical exploration confirmed our clinical suspicion of a superior scleral laceration in the area of the previous cataract wound with iris prolapse through the wound. Subsequent histologic examination confirmed benign melanosis, with pathology revealing numerous regions of subepithelial and substantia propria accumulations of dotlike pigment consistent with uveal pigmentation. Immunohistochemical stains including HMB-45 and S100 confirmed no abnormal melanocytic cells within the epithelium or elsewhere.
The differential diagnosis for pigmentation of the conjunctiva includes several etiologies, as previously mentioned, however new-onset conjunctival pigmentation that is rapidly progressive narrows the top of the differential to acquired melanosis (primary or secondary) and pigmented malignant neoplasia.
Conjunctival melanomas represent about 2% of all ocular malignancies and typically present as focal areas of raised macules, plaques, or masses in an asymptomatic patient, most commonly in the sixth decade.(7,8) Clinical features that may suggest conjunctival melanoma include large size, lack of mobility, limbal location, variegation, and presence of feeder vessels.(8) Conjunctival melanoma may arise from areas of primary acquired melanosis, de novo, or from a conjunctival nevus. Usually melanoma arising from a prior nevus or de novo, appears as black or grey vascularized nodule, whereas lesions arising from PAM with atypia have areas of nodularity and thickening. Conjunctival melanoma can also present as an amelanotic lesion with a pink, smooth “fish-flesh” appearance.(9) Whereas our patient demonstrated large areas of new conjunctival pigmentation, the history was significant for recent blunt trauma to the eye. Additionally, histological examination our patient’s conjunctiva confirmed that the deposition of pigment cells was not in the epithelial layer but rather deeper within the subepithelial layer and substantia propria.
Our patient’s medical history may have predisposed her to scleral perforation after blunt trauma. First, she has a history of cataract extraction performed through a superior scleral tunnel incision. Expulsive iridodialysis secondary to trauma has been noted in several case reports as a rare complication of blunt trauma to eyes that have undergone previous cataract surgery.(10-13) Second, our patient suffers from rheumatoid arthritis. Because there is an association between scleral thinning and perilimbal scleromalacia, she may have additionally been predisposed to scleral perforation after blunt trauma.(14,15)
Several case reports describe secondary acquired conjunctival melanosis after ocular trauma or surgery including intrableb pigmentation (IBP) after trabeculecomy and phacoemulsification,(2,3) pigmentation following pars-plana vitrectomy,(4) and pigmentation attributable to a surgical clamp.(5)
A similar case report by Benson et al describes centrifugal pigment dispersion diffusely throughout the conjunctiva following traumatic scleral perforation with iris incarceration.(6) Electron microscopy of conjunctival tissue from this case revealed many pigment-laden cells in the conjunctival substantia propria closely resembling the melanosomes found in the normal posterior iris pigmented epithelium. Presumably the incarcerated iris in both our case and this published case led to dispersion of iris pigment from mechanical forces rapidly into the conjunctiva.
Our patient’s rapid development of secondary acquired conjunctival pigmentation was a direct result of a perforating scleral injury with uveal tissue prolapse, and although uncommon, should be considered in the differential diagnosis for melanosis after trauma.
Acknowledgments
The authors wish to thank Walter Beebe, MD, and Dr. Robert Nick Hogan, MD, PhD, for their collaboration on case history, photographs, and histopathology. | |
|
|
|
|
|
|
Welcome, please sign in 
