Cases Of Primary Acquired Melanosis Research Articles

Clinical and Histopathological Features of Corneal Primary Acquired Melanosis and Melanoma

Aim: The aim of this study is to describe the clinical and pathologic features of corneal primary acquired melanosis (PAM) and melanoma. Methods: We describe 3 cases in total: two cases of corneal melanomas and 1 case of corneal PAM. The eyes were processed routinely for histopathological examination. Clinical histories, treatments, and outcomes were reviewed. Results: Corneal melanomas arose from recurrence of conjunctival melanoma or conjunctival PAM at the limbus. One patient had a recurrence after excision of a limbal melanoma, another had a de novo corneal melanoma, and the last patient had corneal PAM in the setting of conjunctival PAM with atypia. All lesions were excised with adjuvant alcohol debridement and cryotherapy with no recurrence ranging from 1 week to 8 years. Conclusions: Corneal melanomas arise at the limbus from corneal PAM or conjunctival atypia. They can appear after excisional removal of a conjunctival melanoma. Surgical excision with alcohol debridement and adjuvant cryotherapy is successful.

Primary acquired melanosis: A unique presentation

to report a case of PAM with atypical presentation We are reporting a case of a 45 years old male who presented to the outpatient department of Ophthalmology with complaints of sudden onset watering and foreign body sensation in the right eye. Detailed slit lamp examination revealed an elevated pigmented lesion of the conjunctiva in the nasal quadrant extending up to 2 clock hours. Excision biopsy was done and histopathological examination found the lesion to be moderate grade dysplastic conjunctival PAM. Primary acquired melanosis (PAM) is an acquired disorder of the conjunctiva characterized by a flat brown pigmentation of the conjunctival epithelium. It may be analogous to lentigo maligna — a preinvasive epidermal pigmentation of skin. It presents as a unilateral patchy area of conjunctival pigmentation mostly seen in middle aged or elderly light skinned individuals with a potential for malignant transformation.

C-Kit SCF receptor (CD117) expression andKITgene mutation in conjunctival pigmented lesions

To investigate the presence of KIT gene mutations and immunoreactivity in 85 conjunctival melanocytic tumours and to clarify the role of KIT as a potential therapeutic target in this group of patients. Eighty-five conjunctival pigmented tumours [27 melanomas, 12 primary acquired melanosis (PAMs) and 46 nevi] were immunostained for KIT. Intensity and pattern of expression were evaluated. Molecular analysis to identify KIT mutations was performed in 15 selected cases (tumour-rich areas >50%). KIT immunostaining score and pattern were statistically related to patients' age, sex, diagnostic category, presence of relapse, disease-free survival, presence of metastases, metastasis-free survival, limbal versus nonlimbal tumour location and thickness of melanomas. KIT stains were documented in 48% of melanomas, 50% of PAMs and 24% of nevi. The mean score of KIT staining in the melanomas/PAMs group was significantly different from nevi (p = 0.0076). No statistically significant differences were detected between either c-kit immunostaining score or pattern and each of the other clinico-pathologic parameters considered. No KIT gene mutations were detected in melanomas and nevi. A silent mutation/polymorphism in KIT exon 13 was found in one PAM. Despite the high level of KIT immunostains in PAMs and melanomas, this parameter seems not to be a good predictor of the presence of molecular mutations. KIT-activating mutations should be considered an uncommon event in this tumour.

Complications of management in primary acquired melanosis with atypia

The management of conjunctival primary acquired melanosis (PAM) with atypia is in flux. Lesions are treated with biopsy, excision, adjunctive cryotherapy, or topical mitomycin.1 Acceptable, usually minimal, complications have been...

Primary Acquired Melanosis of the Conjunctiva: Risks for Progression to Melanoma in 311 Eyes: The 2006 Lorenz E. Zimmerman Lecture

To evaluate the clinical features and risks for transformation of conjunctival primary acquired melanosis (PAM) into melanoma. Noncomparative case series. Three hundred eleven eyes with conjunctival PAM without melanoma at initial examination from a single-center tertiary referral center. Retrospective chart review with evaluation of the clinical features of PAM at initial presentation and follow-up. Times to PAM enlargement, recurrence, and transformation into melanoma were assessed using Kaplan-Meier estimates. Risk factors for these outcomes were analyzed using Cox proportional hazards regressions. Primary acquired melanosis enlargement, recurrence, and transformation into melanoma. Mean patient age at diagnosis of PAM was 56 years (range, 15-90), 62% were female, and 96% were Caucasian. The conjunctival quadrant(s) affected by PAM were temporal (57%), inferior (45%), nasal (42%), and superior (37%). The anatomic location(s) of PAM included bulbar conjunctiva (91%), limbal conjunctiva (55%), cornea (23%), forniceal conjunctiva (13%), palpebral conjunctiva (12%), and caruncle (11%). Primary acquired melanosis extended for a mean of 3 clock hours (range, 1-12). Initial management included observation (n = 194 eyes [62%]), biopsy combined with cryotherapy (n = 107 eyes [34%]), and topical chemotherapy and/or cryotherapy without biopsy (n = 10 [4%]). Of PAM that was observed, Kaplan-Meier estimates at 10 years revealed PAM enlargement in 35% and transformation into melanoma in 12%. Of those that underwent incisional or excisional biopsy, 10-year estimates of PAM recurrence and transformation into melanoma were 58% and 11%, respectively. Progression to melanoma occurred in 0% of cases of PAM without atypia, 0% of cases of PAM with mild atypia, and 13% of cases of PAM with severe atypia. Of the 9 patients with PAM who developed melanoma, none have developed systemic metastasis. Multivariable analysis revealed that the most significant factor for both PAM recurrence and progression to melanoma was extent of PAM in clock hours. Primary acquired melanosis without atypia or with mild atypia shows 0% progression to melanoma, whereas PAM with severe atypia shows progression to melanoma in 13%. The greater the extent of PAM in clock hours, the greater the risk for transformation to melanoma.

Low-risk and High-risk Histologic Features in Conjunctival Primary Acquired Melanosis With Atypia: Clinicopathologic Analysis of 29 Cases

The current World Health Organization classification of conjunctival melanocytic proliferations divides them into conjunctival nevi and invasive melanoma but, in contrast to other anatomic sites, does not recognize melanoma in situ. All atypical intraepithelial conjunctival proliferations are included in a heterogeneous category designated as primary acquired melanosis (PAM) with atypia. We performed clinicopathologic analysis of 29 cases of PAM with atypia. On the basis of histologic features and frequency of association with invasive melanoma and metastases, we were able to divide our cases into 2 histologic groups. The low-risk group (13 cases) included lesions composed of small to medium size melanocytes with high nuclear to cytoplasmic ratio and small to medium size hyperchromatic nuclei devoid of nucleoli showing predominantly single cell lentiginous growth pattern. Invasive melanoma occurred in only 2 cases from this group. None of these lesions metastasized. The second, high-risk group (16 cases), showed increased frequency of association with invasive melanoma (15/16 cases, 94%) and metastases (4/16 cases, 25%). These lesions were more heterogeneous architecturally but were all composed of melanocytes showing various degrees of epithelioid features such as abundant cytoplasm, vesicular nuclei, or prominent nucleoli. In 4 cases discrete areas showing high-risk and low-risk features were identified. All 4 lesions were associated with invasion. Our findings offer a practical approach for prognostically useful subclassification of PAM with atypia, which emphasizes cytologic features of intraepithelial conjunctival melanocytic proliferation.

Differential immunoreactivity of melanocytic lesions of the conjunctiva.

To evaluate the expression of S100NKI/C3 and HMB45 antigens in melanocytic lesions of the conjunctiva and the ability of HMB45 to aid assessment of neoplasia. Stored formalin-fixed specimens of conjunctival melanomas and primary acquired melanosis were considered as participants and conjunctival naevi and racial melanosis as controls. Ninety-seven conjunctival melanocytic lesions were analysed using formalin-fixed paraffin-embedded material. These included 20 melanomas arising in the context of primary acquired melanosis (PAM), 22 melanomas arising without evidence of pre-existing PAM, seven cases of PAM with atypia, nine cases of PAM with no atypia, 35 conjunctival naevi and four cases of racial melanosis. S100 and NKI/C3 were similarly expressed in all lesions, with at least one of these markers positive in 100% of the lesions examined. HMB45 was expressed in 72.7% of primary melanomas and 85% of melanomas in the context of PAM; 42.8% of PAM with atypia expressed HMB45 while it was expressed in 11.1% of PAM without atypia and 8.5% of naevi. Racial melanosis cases did not express HMB45. S100 and NKI/C3 were expressed to a similar extent in all groups. S100 and NKI/C3 are useful markers to assess the extent of melanocytic lesions in the conjunctiva. HMB45 immunoreactivity can act as a useful aid to histopathology for the distinction of benign from malignant conjunctival lesions, particularly in the context of primary acquired melanosis.