Primary atypical lipomatous tumor of the orbit: A case report

Abstract

Purpose:To describe a case of primary atypical orbital lipomatous tumor (ALT).Case Report:A 35-year-old man presented with a two-month history of left eye proptosis and vertical diplopia. His visual acuity was 20/30 OD and 20/60 OS. External examination showed proptosis and downward displacement of the left eye with mild lid erythema. Extraocular movements were reduced in the left eye, with 10% and 70% motility in upgaze and abduction/adduction, respectively. Imaging showed a mass (22 × 16 × 46 mm) in the superior left orbit that infiltrated the orbital fat and the superior rectus muscle. A biopsy of the mass showed mature adipose tissue intermingled with fibrous zones of hyperchromatic stromal cells with nuclear atypia. Fluorescence in situ hybridization analysis demonstrated positive amplification for MDM2/CEP12. The MDM2 to CEP12 ratio was 5:7. A diagnosis of ALT was confirmed. An orbital exenteration was recommended, which the patient declined.Conclusion:Although rare, the differential for unilateral proptosis with or without diplopia should include orbital liposarcomas including the ALT subtype. Imaging, biopsy, staining, and/or FISH analysis for proto-oncogenes can assist with diagnosis and staging, while the standard treatment is exenteration.

Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma of the Orbit: Three Cases and Review of the Literature

“…1,3,7,9–11,15,16,20 While ALT/WDL tumors make up 40% to 45% of liposarcomas, 21 the majority of liposarcomas involving the orbit were previously reported to be of the myxoid type (57%), followed by ALT/WDL (30%) and pleomorphic (11%). 1 However, upon the authors’ review of 63 documented cases of primary orbital liposarcoma in the English literature (including the authors’), 42.9% (n = 27) were ALT/WDL, 2–16 39.7% (n = 25) were myxoid, 1,7,13,20,22–33 8.9% (n = 6) were pleomorphic, 1,3,22,34–36 and 7.5% (n = 5) were dedifferentiated liposarcomas. 3,20,37–39 Excluding dedifferentiated cases, the breakdown was found to be 46.5% ALT/WDL, 43.1% myxoid, and 10.3% pleomorphic liposarcoma, suggesting that ALT/WDL is more common in the orbit than previously thought.…”

“…12 One study had utilized comparative genomic hybridization to detect chromosomal abnormalities, and 6 of the cases had detected MDM2 amplification with FISH. 6,9,12,15,16 Utilization of molecular studies may be of significant value particularly in cases with overlapping features of other lipomatous tumors and conditions. McKey et al 16 demonstrated a case of a spindle cell/pleomorphic lipoma (based on histopathological features) until it was confirmed to be ALT/WDL by FISH, which demonstrated amplification of MDM2 and CDK4 .…”

“…19 Radiographically, the tumor may present variably as an extraconal or intraconal mass with or without involvement of the extraocular muscles. 1,3,7,[9][10][11]15,16,20 While ALT/WDL tumors make up 40% to 45% of liposarcomas, 21 the majority of liposarcomas involving the orbit were previously reported to be of the myxoid type (57%), followed by ALT/WDL (30%) and pleomorphic (11%). 1 However, upon the authors' review of 63 documented cases of primary orbital liposarcoma in the English literature (including the authors'), 42.9% (n = 27) were ALT/ WDL, 2-16 39.7% (n = 25) were myxoid, 1,7,13,20,22-33 8.9% (n = 6) were pleomorphic, 1,3,22,34-36 and 7.5% (n = 5) were dedifferentiated liposarcomas.…”

“…To date, there have been 24 cases (27, including the authors') documented in the English literature with a diagnosis of ALT/WDL of the orbit. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] In the authors' review, 17 out of the 27 cases had utilized immunohistochemical staining to help confirm their diagnosis. 1,3,4,6,[9][10][11][12]15,16 Two cases had utilized immunohistochemical staining for MDM2.…”

Primary Atypical Lipomatous Tumor of the Orbit

“…I read with interest the case report by Dworak et al on orbital atypical lipomatous tumor (ALT), a rare variety of liposarcoma, in an American patient. [1] It is obvious that in addition to opportunistic infections, patients infected with human immunodeficiency virus (HIV) are also more susceptible to various types of tumors. The origin of these tumors is thought to be multifactorial, including immunosuppression, co-infection with oncogenic viruses, and life prolongation secondary to the use of antiretroviral therapy.…”