Lin Sandra M, Ferrucci Steven
VA Greater Los Angeles Healthcare System, Sepulveda Ambulatory Care Center and Nursing Home, Sepulveda, California 91434, USA.
Optometry. 2006 May;77(5):223-8. doi: 10.1016/j.optm.2006.02.007.
Primary acquired melanosis (PAM) presents as a unilateral patchy area of conjunctival pigmentation mostly found in middle-aged or elderly white patients. Because PAM has the potential of becoming malignant, it is important to recognize PAM and to rule out other causes of pigmented lesions. The presence or absence of atypia is helpful in determining the potential for malignancy, because PAM without atypia is usually benign, whereas PAM with atypia may convert into a conjunctival melanoma. If atypia is present, the presence or absence of epithelioid cells and the pattern of intraepithelial growth are the main factors in determining the likelihood of neoplastic transformation. However, atypia can only be determined with histopathologic examination. Therefore, a biopsy is usually recommended.
A 72-year-old white man presented for his annual examination with no visual complaints. His ocular history was remarkable for early cataracts and for a choroidal nevus. Slit lamp examination found a large dark area of elevated conjunctival pigmentation at the medial canthus that extended onto the superior bulbar conjunctiva and superior palpebral conjunctiva in the left eye. No conjunctival pigmentation had been noted previously. Results of a biopsy indicated primary acquired melanosis with atypia. The lesion was surgically excised, and the conjunctiva was reconstructed with an amniotic membrane graft. The patient was subsequently treated with topical 5-fluorouracil chemotherapy. There have been no signs of recurrence to date after his treatment.
Because of the potential for malignancy, biopsies of all cases of primary acquired melanosis are indicated. If atypia is present, treatment options include local excision, cryotherapy, and topical chemotherapy.
原发性后天性黑变病（PAM）表现为结膜色素沉着的单侧片状区域，多见于中老年白人患者。由于PAM有恶变的可能，识别PAM并排除色素沉着病变的其他原因很重要。非典型性的存在与否有助于确定恶变的可能性，因为无非典型性的PAM通常是良性的，而有非典型性的PAM可能会转变为结膜黑色素瘤。如果存在非典型性，上皮样细胞的存在与否以及上皮内生长模式是决定肿瘤转化可能性的主要因素。然而，非典型性只能通过组织病理学检查来确定。因此，通常建议进行活检。
一名72岁白人男性因年度检查前来就诊，无视力方面的主诉。他的眼部病史有早期白内障和脉络膜痣。裂隙灯检查发现左眼内眦有一大片隆起的结膜色素沉着暗区，延伸至上睑结膜和上睑球结膜。此前未发现结膜色素沉着。活检结果显示为伴有非典型性的原发性后天性黑变病。病变通过手术切除，结膜用羊膜移植片重建。患者随后接受了局部5-氟尿嘧啶化疗。迄今为止，他接受治疗后没有复发迹象。
由于存在恶变的可能性，所有原发性后天性黑变病病例均需进行活检。如果存在非典型性，治疗选择包括局部切除、冷冻疗法和局部化疗。
