ABSTRACT
Purpose@#We report a case of phakomatous choristoma presenting as an orbital tumor with involvement of the inferior oblique muscle. Case summary: A 2-month-old male infant presented to our clinic with a right orbital mass that had been present since birth. Magnetic resonance imaging demonstrated a homogenous enhanced well-defined mass located in the inferomedial portion of the right orbit without bone erosion. By transconjunctival orbitotomy, the orbital tumor invading the inferior oblique muscle was identified and resected. Histopathology showed a thick basement membrane surrounding pseudoglandular structures embedded in a collagenous stroma, psammomatous calcific foci in the stroma, and eosinophilic material in the lumen. Immunohistochemical analysis showed positive staining for S-100 and cytokeratin. On histopathological evaluation, the tumor was diagnosed as phakomatous choristoma. @*Conclusions@#To our knowledge, this is the first report in South Korea of phakomatous choristoma of the orbit with involvement of the inferior oblique muscle. Although rare, phakomatous choristoma should be included in the differential diagnosis of tumors occurring on the inferomedial side of the orbit.
ABSTRACT
Purpose@#This study assessed the effects of bilateral inferior oblique myectomy for hypertropia on the preoperative vertical deviation angle in patients with asymmetric primary inferior oblique overaction (IOOA). @*Methods@#This study included patients who underwent bilateral inferior oblique myectomy and lateral rectus recession due to asymmetric primary IOOA and intermittent exotropia, and were followed up for at least 6 months postoperatively. Pre- and post-operative vertical deviation angles were compared. The correlation between the extent of correction of vertical deviation after surgery and residual hypertropia, according to the preoperative degree of vertical deviation and difference between bilateral IOOA, was evaluated. @*Results@#This study included 178 eyes from 89 patients. The angle of hypertropia in the primary position was reduced from 3.2 ± 2.2 prism diopters (PD) preoperatively to 0.5 ± 2.5 PD postoperatively (Wilcoxon signed-rank test, p < 0.001). No significant correlation was observed between the preoperative interocular difference in IOOA and postoperative extent of correction of the vertical deviation (r = 0.044, p = 0.684), or between the preoperative difference in bilateral IOOA and residual hypertropia (Spearman's rank-order correlation, r = -0.084, p = 0.432). Increased preoperative hypertropia correlated with a greater extent of surgical correction of the vertical deviation (r = 0.733, p < 0.001). Preoperative hypertropia had no significant correlation with residual hypertropia (Spearman's rank-order correlation, r = 0.182, p = 0.087). @*Conclusions@#In symmetric bilateral inferior oblique myectomy with bilateral lateral rectus recession for asymmetric bilateral primary IOOA with V-type intermittent exotropia, a positive correlation between the degree of preoperative vertical deviation and extent of correction of the vertical deviation was observed. Additionally, IOOA and hypertropia were significantly improved postoperatively.
ABSTRACT
Purpose@#We report a case of phakomatous choristoma presenting as an orbital tumor with involvement of the inferior oblique muscle. Case summary: A 2-month-old male infant presented to our clinic with a right orbital mass that had been present since birth. Magnetic resonance imaging demonstrated a homogenous enhanced well-defined mass located in the inferomedial portion of the right orbit without bone erosion. By transconjunctival orbitotomy, the orbital tumor invading the inferior oblique muscle was identified and resected. Histopathology showed a thick basement membrane surrounding pseudoglandular structures embedded in a collagenous stroma, psammomatous calcific foci in the stroma, and eosinophilic material in the lumen. Immunohistochemical analysis showed positive staining for S-100 and cytokeratin. On histopathological evaluation, the tumor was diagnosed as phakomatous choristoma. @*Conclusions@#To our knowledge, this is the first report in South Korea of phakomatous choristoma of the orbit with involvement of the inferior oblique muscle. Although rare, phakomatous choristoma should be included in the differential diagnosis of tumors occurring on the inferomedial side of the orbit.