P 106 The subpopulation of lymphocytes infiltrating in the keratoconjunctival squamous cell carcinoma

Backarcund: Merkel cell carcinoma is a highly malignant cutaneous neoplasm with a high rate of local recurrence and systemic metastasis. Ten percent of all Merkel cell carcinomas involve the periocular region. We present three pStiSfltS. Patients and Methods: Patient 1 (B.H.). 86-year-old male presenting with a painless reddish tumor involving two thirds of the right upper eyelid and a basal cell carcinoma of the lateral lower eyelid centrally. Wide surgical excision with full thickness resection of the eyelid and reconstruction using a semicircular flap were performed. Patient 2 (Sch.K.): 8%year-old female presenting with a curclish tumor invclvinc the central two thirds of the lefl uccer evelid. Wide full ihidkness resection of-the eyelid was done. Reccnstru&n &as performed using e Cutler-Beard bridge flap. Patient 3 (M.Ch.): 78-year-old female presenting with a reddish tumor involwng the left eyebrow laterally. Wide excision was done and reconstruction was performed using sliding flaps. No patient showed evidence of systemic disease. The excised specimens were processed for histopathologic. immunhislochemical and electron microscopic studies. w Histopathologically. the tumcr cells showed round-to-oval unifom, nuclei with finely dispersed chromatic. and one to three inconspicuous nucleoli. Mitctic figures were numerous. lmmunh~stochemical studies showed positive reactions for NSE. cytokeratin 18 and chrcmogranin A. Electron microscopy revealed membrane-bound, dense core granules. After a follow-up of 3 years, there was no evidence of local recurrence or systemic metastasis in 2 patients. Conclusions: Characteristic features of M#?lXel cell Mrcincma include a reddish m hematcus hue and a fast tumor growth. Therapy of choice is wide Sumica of the mass w'th a suacested mamin of 8 mm. prefere&lly with frozen section control. Immu&tcchemicai and electron microscopic studies may be helpful in establishing the diagnosis and differentiating this tumcr from other 6ccrly differentiated%eoplasms:-WC investigated the subpopulation of lymphocytes infiltrating in the kcratoconjunctival squamous cell carcinoma. &@c& Five specimens embedded in paraffin were sectioned and stained with immunohistochemical technique. Used primary antibodies were LCA, MT-I, UCHL-I and L-26. The number of positive cells for each primary nntibcdy were counted and positive rates were calculated. m In three spccimcns. lymphccytcs were infiltrated deeply irito the cell nest af the tomcra. Almost all of these lymphocytes were T lymphocytes. In the other twc specimens. few lymphocytes were infiltrated into the cell nest of the tcmcrs. fhclrrsiorrs The keratoconjunctivl squamous cell carcinoma is under the immunological surveillance by the host. The degree of the immunological rcgdation by the host vary …