Conjunctival Pigmented Actinic Keratosis - a Case Report

The Korean Journal of Pathology 2004; 38: 113-5

Conjunctival Pigmented Actinic Keratosis - A Case Report -

Jinyoung Yoo∙Ji Han Jung We recently had a case of pigmented actinic keratosis arising in the conjunctiva, and this is Hyun Joo Choi∙Seok-Jin Kang an unusual site for the lesion. Most actinic keratoses are seen on sun-exposed areas of the Chang-Suk Kang skin, especially for Caucasians living in sunny climates. When these lesions are pigmented, they may resemble lentigo maligna. A 56-year-old man was referred to the ophthalmology clinic Department of Pathology, St. Vincent’s for a pigmented conjunctival lesion. An ophthalmologic examination revealed multiple dark brown- Hospital, the Catholic University of Korea, colored, linear or irregular shaped patches located on the lateral side of the conjunctiva in his Suwon, Korea right eye, partially covering the cornea, and this made a clinical differentiation from other possible pigmented lesions somewhat difficult. A histologic examination of the subsequent biopsy Received : July 15, 2003 specimen demonstrated acanthosis with melanocytes containing heavy melanin, scattered Accepted : March 2, 2004 dyskeratotic cells, atypical keratinocytes, and solar elastosis, and all of their findings are con- sistent with pigmented actinic keratosis. Corresponding Author Seok-Jin Kang, M.D. Department of Pathology, St. Vincent’s Hospital, the Catholic University of Korea, 93 Chi-dong, Paldal-gu, Suwon 442-723, Korea Tel: 031-249-7591 Fax: 031-244-6786 E-mail: [email protected] Key Words : Dermatitis, actinic-Keratosis-Conjunctiva

Actinic keratoses are usually seen as multiple lesions in the sun- mented areas were located on the lateral side of the conjunctiva exposed skin of older individuals. The face, scalp, ears, hands and and these areas consisted of four linear or irregular shaped pig- forearms are usual sites of predilection.1 The pigmented type of mented patches, the largest being about 8mm in length (Fig. 1). actinic keratosis is a rare premalignant lesion that can be difficult Their surfaces appeared smooth and the borders were irregular, to distinguish from other benign and malignant pigmented le- but well demarcated. One of the pigmented patches was covering sions, including seborrheic keratosis, senile lentigo, melanocytic the cornea. The eyelid was not involved and regional lymphade- nevus, lentigo maligna, and lentigo maligna melanoma.2 nopathy was absent. The results of a subsequent histologic exam- We have recently seen a patient with pigmented actinic ker- ination demonstrated irregular acanthosis with scattered dysker- atosis arising in the conjunctiva, with this being a most unusual atotic cells. Some of the keratinocytes that were present appeared location for the lesion. To the best of our knowledge, no such lesions atypical. Many melanocytes containing melanin were observed have been previously reported in the literature. So we report here- throughout the epidermis (Fig. 2, 3), and there was the basal layer on this unique case, together with a review of the literature. of pigmentation. Solar degeneration with a few melanophages was noted in the superficial subepithelial layer. The surrounding normal epithelium lacked any unusual pigmentation. Fontana- CASE REPORT Masson’s stain highlighted diffuse pigmentation through the full thickness of the epidermis; this pigmentation was also in the me- A 56-year-old man sought medical attention for a recent dec- lanocytes and the intercellular spaces (Fig. 4). On immunohisto- rease in visual acuity. His past medical history was unremarkable. chemical stains, the melanocytes were positive for S-100 protein, A physical examination revealed no other abnormalities. A local but they were negative for HMB-45 (Fig. 5). These findings sup- ophthalmologist noticed a dark brown conjunctival lesion in his ported the diagnosis of pigmented actinic keratosis of the con- right eye and he referred this patient to our institution. The pig- junctiva.

113 114 Jinyoung Yoo∙Ji Han Jung∙Hyun Joo Choi, et al.

Fig. 1. Multiple linear or irregular shaped pigmented patches (ar- Fig. 2. The lesion shows an acanthotic epithelium with dysplasia, rows) are present on the lateral side of the conjunctiva. and marked subepithelial solar degeneration. Higher power view reveals a few mitoses.

A B

Fig. 3. Another area shows acanthosis with pigmentation (A), and Fig. 4. Fontana-Masson’s stain highlights pigmentation in the den- atypical keratinocytes with an atypical mitotic figure (arrow) (B). dritic cells and intercellular space.

DISCUSSION melanophages may be observed in the superficial dermis. The increase in dermal melanophages may reflect an abnormal degran- Actinic keratoses are seen most frequently on the face and the ulation of melanosomes. In the pigmented type of actinic kerato- dorsum of the hands of persons in or past their middle life.3 Exces- sis, very excessive amounts of melanin are present, especially in sive exposure to sunlight is known to be the essential predispos- the basal cell layer, but its etiology is not different from other ing factor. Some melanization is not uncommon and numerous types of actinic keratosis.4 Conjunctival actinic keratosis has been Conjunctival Pigmented Actinic Keratosis 115

of all layers of the epidermis exclude this possibility of some blocks of melanin transfer.2 In our current case, all the melanin granules were present in the dendritic cells and intercellular spaces. Thus, we believe that the abnormal pigmentation of the conjunctival lesion may be due to a disturbance in the melanosome transfer pathway from melanocytes to epithelial cells, and there could be a possible defect in the uptake of melanin by keratinocytes. The exact mechanism, however, should be clarified. Pigmented actinic keratoses need to be separated from lentigo maligna by histological testing because the prognosis and man- agement of these two conditions differ. The epidermis of the lentigo maligna is atrophic with a reduction of rete ridges and there is a proliferation of abnormal melanocytes in the basal layer.1,3,4 This condition stands in contrast with the mildly hyperplastic epidermis of the actinic keratosis that contains atypical keratinocytes with normal-looking melanocytes along the basal layer. A B However, when the vacuolated cells are present, especially in a Fig. 5. Immunohistochemistry after depigmentation shows positivity small biopsy specimen, vacuolated-pigmented keratinocytes in for S-100 protein (A) but negativity for HMB-45 (B). pigmented actinic keratosis may be indistinguishable from the rarely reported5,6 but this pigmented type we observed has never melanocytes of lentigo maligna. Immunohistochemical staining appeared before in the literature. The patient previously reported for S-100 protein and HMB-45 may provide the assistance nec- on in France was a 73-year-old man and he demonstrated the essary in the determination of the abnormal proliferation of int- same findings as shown in our case, including acanthosis with raepithelial melanocytes of lentigo maligna. some atypia, keratosis, parakeratosis, and solar degeneration.6 Mauriello et al.5 reviewed the charts of forty-five patients with intraepithelial neoplastic lesions of the conjunctiva that were REFERENCES obtained from the registry of Ophthalmic Pathology Division of the Armed Forces Institute of Pathology (AFIP). Twenty four 1. Weedon D. Skin Pathology. 2nd ed. London: Livingston, 2002; 761-2. of those cases had actinic keratosis and 21 had dysplasia. The 2. Dinehart SM, Sanchez RL. Spreading pigmented actinic keratosis. lesions classified as actinic keratosis tended to be focal and leuko- Arch Dermatol 1988; 124: 680-3. plakic, whereas those classified as dysplasia tended to be diffuse 3. Elder D, Elenitsas R, Jaworsky C, Johnston B Jr. Lever’s Histopathol- and gelatinous. Two of the lesions of actinic keratosis and 13 of ogy of the skin. 8th ed. Philadelphia: Lippincott, 1997; 701-5. the lesions of dysplasia recurred during 2 years of follow-up. The 4. James MP, Wells GC, Whimster IW. Spreading pigmented actinic degree of atypia was described to be uncorrelated with recurrence. keraoses. Br J Dermatol 1978; 98: 373-9. The mechanism of hyperpigmentation in pigmented actinic 5. Mauriello JA Jr, McLean NJ. Actinic keratosis and dysplasia of the keratosis is not yet clear. Although the atypical keratinocytes are conjunctiva: a clinicopathologic study of 45 cases. Can J Ophthalmol well melanized in some cases, melanin is exclusively contained in 1995; 30: 312-6. the cell bodies and dendrites of the melanocytes in others. There- 6. Mortemousque B, Leger F, Brindeau C, Dorot N, Barac’h D, Verin P. fore, it has been postulated that the hyperpigmentation in pig- Actinic keratosis of the conjunctiva. J Fr Ophthalmol 1998; 21: 458-61. mented actinic keratosis may be due to a melanocyte-keratinocyte 7. Salibury JA, Szpak CA, Klintworth GK. Pigmented squamous carci- melanin transfer block.4 This is supported by the fact that inc- noma of the conjunctiva. Ophthalmol 1983; 90: 1477-81. reased number of melanosomes were seen within melanocytes 8. Zelickson AS, Goltz RW, Hortmann JF. A histological and electron of pigmented basal cell epitheliomas.7,8 However, the findings microscopic study of a pigmented basal cell epithelioma. J Invest of melanosomes and melanosome complexes in the keratinocytes Dermatol 1961; 36: 299-302.