Eccrine Hidrocystoma Arising at the Tarsal Plate during Childhood
A 5-month-old boy was referred to us for further examination of his right upper-eyelid tumor. The tumor was 8 mm in diameter and observed in the upper eyelid (fig. ). According to his parents, the tumor was first noticed at the child's birth. As the patient could open his eye, it was assumed that the tumor most likely would not affect the visual development in his right eye. Therefore, at that time, we decided that a follow-up examination was the best option for the patient. However, due to a gradual enlargement of the tumor, the patient returned 2 years later and underwent further evaluation (fig. ). At the time of the follow-up examination, the tumor exhibited a distinct boundary and was 12 mm in size. Physical examination revealed that there was no pain or any inflammatory reaction in the lid. When observed from the side of the palpebral conjunctiva, the tumor was found to be buried beneath a portion of the tarsal plate and showed a translucent configuration (fig. ). A T2-enhanced magnetic resonance imaging (MRI) examination demonstrated that the tumor was well demarcated from the surrounding tissue. This uniformly high-intensity lesion was 12 mm (height) × 12 mm (width) × 8 mm (depth) in size, with the lesion observed to be in direct contact with the tarsal plate (fig. ). Since the tumor caused blepharoptosis in the patient's right eye, this subsequently led to oblique astigmatism. Therefore, 2 months later, it was decided to surgically remove the mass lesion. The wall of the tumor was easily separated from the surrounding connective tissues, with the exception of the portion where the tarsal plate was attached. As a result, the tumor was completely removed along with a round defect of the tarsal plate (fig. ). Pathological examination showed that the tumor was composed of a thin wall and contained a transparent liquid. The wall consisted of a single cuboidal epithelium that covered the inner luminal surface without decapitation. An area of papillary process proliferation was also observed (fig. ). Based on these findings, the tumor was diagnosed as eccrine hidrocystoma. Although there was obvious improvement in the blepharoptosis after the surgery, his best-corrected visual acuities remained at 0.2 OD and 1.2 OS due to the refractive astigmatic amblyopia that was present at 2 weeks after the procedure. Thus, the patient was provided with a prescription for glasses and, with the help of his parents, began a training program designed for the visual recovery of his right eye. Two years later, his best-corrected visual acuities recovered to 1.0 OD (fig. ).