AIM: To evaluate the ophthalmic manifestations, radiographic features, and prognosis of Chinese patients with primary orbital mesenchymal chondrosarcoma (MCS). METHODS: The study included 6 cases with primary orbital MCS treated at Tianjin Eye Hospital from January 2009 to December 2019. Patitent ophthalmic manifestations, radiographic features, diagnosis, pathology, therapeutic regimens, and prognosis were retrospectively reviewed. RESULTS: Six patitents with primary orbital MCS were identified. The mean age at the first visit was 33y (range, 25-42y). All six patients displayed manifestations of exophthalmos, diplopia, limitation of eye displacement, upper eyelid oedema, decreased visual acuity and ptosis. The mean disease history and range were 5 and 2-8mo, respectively. The tumors were located in the superonasal extraconal compartment (2/6, 33.3%), intraconal compartment (2/6, 33.3%), and bitemporal extraconal compartment (2/6, 33.3%), respectively. Radiographic features were a well-defined, orbital mass with calcification and ossification on computed tomography (CT), and marked heterogenous enhancement on dynamic magnetic resonance imaging (MRI). Five patients were treated with tumor resection and one patient received orbital exenteration. Five patients in the cohort received postoperative radiation therapy, two patients received chemotherapy, and one patient did not receive postoperative adjuvant therapy because he refused. The histopathologic classification revealed a tumour composed of a mixture of mature chondroid tissue surrounded by small, round, and undifferentiated mesenchymal cells. Immunohistochemistry revealed Bcl-2, vimetin, CD99, and S-100 were expressed were expressed. After surgeries, two patients have developed a local recurrence. The median recurrence time of 58mo (52-64mo). One patient had distant recurrence included the lungs occurred 52mo after the initial surgery. CONCLUSION: The possibilty of orbital MCS need to be considered when a painless, slowly growing orbital mass with calcification and ossification. From our experience, trimodality treatment of radiation therapy, chemotherapy and surgery maybe the best option. Orbital MCS has a high tendency for late recurrence, regular long-term follow-up after complete excision is mandatory.

Background To review the clinical features, radiographic features, therapy, pathological features and prognosis of orbital cholesterol granuloma(CG). Methods Twelve patients with orbital CG who were referred to Tianjin Eye Hospital between January 2002 and December 2020 were include in this retrospective case series study. Data collected included patient ophthalmic manifestations, imaging finding, treatment strategies, pathological features and prognosis were retrospectively reviewed. Results The patients comprised 10 males and 2 females. The mean age was 34.5±8.9 years(range 16 to 45 years). Four patients had a history of orbital trauma. The clinical manifestations at first visit were proptosis ( 7/12, 58.3%), periorbital or eyelids swelling (6/12,50%), limitation of eye displacement (4/12,33.3%), ptosis(2/12,16.7%), decreased visual acuity (1/12,8.3%).CT showed a non-enhancing,well-circumscribed lesion in the orbit with extensive erosion of the adjacent frontal bone and temporal bone.MRI showed a non-enhancing mass with intermediate to high signal intensity on T1- and T2-weighted imaging. Ten patients underwent lateral orbitotomy, and two patient underwent supraorbital orbitotomy,.All patients had aggressive bone erosion. Histopathologic evaluation of the cyst contents and wall revealed cholesterol clefts,multinucleated giant cells,histiocytes, foamy macrophages,and altered blood pigments. The median recurrence time of 79.6±49.8 months (range 19 month to 193 months). Three patients were lost to follow-up. No postoperative diminution of vision was noted,and no recurrence was observed. Conclusions Cholesterol granulomas can present as superiotemporal or temporal orbital lesions. The diagnosis can be established based on CT and MRI. Most of patients can have no history of orbital trauma.