Pilomatrix carcinoma of the lacrimal caruncle: a case report / Carcinoma pilomatricial da carúncula lacrimal: relato de caso

ABSTRACT A 45-year-old man presented with a 3-month history of a mass located in the caruncle of his right eye. An incisional biopsy had been performed one month prior by another specialist, and the histopathology report showed basal cell carcinoma. The mass was completely excised with a 2 mm safety margin, and the large conjunctival defect was reconstructed with one sheet of amniotic membrane allograft. A histological diagnosis of pilomatrix carcinoma was established. To prevent recurrence after surgery, we added bevacizumab (25 mg/mL, 1.25 mg/mL per drop) eye drops four times per day for three months. At the one-year follow-up, the patient showed no evidence of local recurrence or distant metastasis after initial excision and remains under close follow-up. Pilomatrix carcinoma should be considered in the differential diagnosis of a caruncular mass.

RESUMO Um homem de 45 anos apresentou história de massa na carúncula no olho direito durante 3 meses. Uma biópsia incisional foi realizada 1 mês antes por outro especialista e o laudo histopatológico mostrava carcinoma basocelular. A massa foi completamente excisada, com uma margem de segurança de 2 mm, e a grande lesão conjuntival foi reconstruída com uma folha de aloenxerto de membrana amniótica. Foi estabelecido um diagnóstico histológico de carcinoma pilomatricial. Para evitar a recorrência após a cirurgia, adicionamos colírio de bevacizumabe (25 mg/mL, 1,25 mg/mL por gota) quatro vezes ao dia durante três meses. No seguimento de 1 ano, o paciente não apresentou evidência de recidiva local ou metástase distante após a excisão inicial e continua sob acompanhamento próximo. O carcinoma pilomatricial deve ser considerado no diagnóstico diferencial de uma massa caruncular.

Intravitreal injection of methotrexate in an experimental rabbit model: Determination of ultrastructural changes.

Purpose: To investigate the ultrastructural changes of the rabbit retina induced by intravitreal methotrexate injection. Materials and Methods: Ten New Zealand white rabbits were enucleated bilaterally at different time periods after intravitreal methotrexate injection. One rabbit was used as control group and one rabbit was used as intact group. Histopathological examinations were performed under light and electron microscopy. Early (within first three days after injection) and long-term (one month after serial injections) effects of intravitreal methotrexate on the retina were investigated. Results: Retinal edema, vacuolization, and disintegration of mitochondria of the retinal cells were observed as early changes. The main long-term effects after serial injections were edema in the photoreceptor, inner nuclear, and ganglionic cell layers. Cellular disorganisation was seen on light microscopy. Electron microscopic examination revealed mitochondrial degeneration and vacuole formation in retinal cells, nuclear degeneration in outer nuclear layer, and membranous whorl formation in photoreceptor and nerve fiber layers. Conclusions High dose intravitreal methotrexate injection may cause significant ultrastructural changes in the rabbit retina in varying severity. This finding may highlight the potential side effects of methotrexate on human retina in higher doses.

Intravitreal injection of methotrexate in an experimental rabbit model: Determination of pharmacokinetics.

Purpose: To investigate the pharmacokinetics of intravitreally administered methotrexate. Materials and Methods: Twenty-one New Zealand white rabbits were used in the study. The pharmacokinetics of intravitreally injected 800 μg/0.1 ml of methotrexate was investigated. Intravitreal concentration of the drug was measured at seven different times, in six eyes at each occasion, on a total of 42 eyes of 21 rabbits from a period of 30 minutes to 72 hours. Results: The volume of distribution was calculated as 1.33 ml following intravitreal injection of 800 μg methotrexate. Vitreous concentrations of the drug were found to be decreasing related to the specific mathematical equation; drug concentration= 1426.73 e-0.1182(time) and remained over effective dose by 81 hours with a half life of 5.9 hours. Conclusions: These findings evidenced those vitreous levels of methotrexate at various time intervals after 800 μg intravitreal injections which formulated a mathematical equation for calculation of vitreous level of the drug at each hour.