MDM2-Positive Atypical Lipomatous Neoplasm/Well-Differentiated Liposarcoma Versus Spindle Cell Lipoma of the Orbit

Recurrent primary orbital well-differentiated liposarcoma /atypical lipomatous tumor: A rare case report with six-year follow-up

Purpose

We report a case with over 6 years of follow-up for well-differentiated liposarcoma or atypical lipomatous tumor (WDL/ALT).

Observations

Over a 6-year time course, a patient with a recurrent right orbital mass was biopsied/debulked four times. It was not until the fourth biopsy that a diagnosis of WDL/ALT was obtained. Throughout the time course, the patient maintained good vision and there has been no evidence of dedifferentiation or metastasis thus far.

Conclusions

The diagnosis of WDL/ALT sound be considered in the cases of a recurrent orbit mass when pathology continually shows nonspecific fibrofatty tissue with chronic inflammatory changes.

Epibulbar Proliferative Fasciitis, a Variant of Nodular Fasciitis: A Differential Diagnosis of Conditions With Focal or Diffuse Myxoid Stromas

PURPOSE

To describe the clinical and pathologic features of a case of epibulbar proliferative fasciitis and to compare it with other focal or diffuse myxoid lesions.

METHODS

A clinical, histopathologic, and immunohistochemical analysis was performed. The clinical history, photographic documentation, history, and referred slides were reanalyzed. Additional immunohistochemical stains were performed at our institution.

RESULTS

A 68-year-old woman developed over a week a brightly vascularized and focally hemorrhagic placoid lesion on the temporal side of the OS. She had had earlier augmentation breast surgery that had been mistakenly initially reported to us to be for breast carcinoma. Hematoxylin- and eosin-stained reactions revealed microscopically a spindle cell lesion with an intact nonkeratinizing epithelium and a background myxoid stroma with prominent capillaries and a light dispersion of small T-cell lymphocytes. Most striking among the spindle cells were some widely separated large atypical cells. The atypical cells were cytokeratin positive, but an expansive panel of immunohistochemical stains for breast carcinoma was negative. The lesion was diagnosed as proliferative fasciitis and has not recurred after 1-year follow up.

CONCLUSION

A rapidly evolving conjunctival lesion is unlikely to be a primary or metastatic carcinoma. In the current case, the large ganglioform or rhabdomyoblast-like cells displayed diffuse cytokeratin positivity, still consistent with a mesenchymal or connective tissue cell lineage. Cytokeratin expression has been a finding previously reported in connective tissue tumors and in lymphoma cells. While the current lesion clinically resembles a conventional nodular fasciitis, the presence of the large atypical cells can lead to the misdiagnosis of a sarcoma, which typically displays a much higher Ki-67 proliferation index in comparison with nodular/proliferative fasciitis.

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

The authors present 3 patients from this retrospective case series to review the clinical findings, imaging, pathology, and treatment of orbital atypical lipomatous tumor/well-differentiated liposarcoma. Pathology of biopsy specimens ranged from spindle cell proliferations mimicking neurofibroma to proliferations of well-differentiated adipocytes. Immunohistochemical stains were positive for murine double minute 2 in 1 case, and fluorescent in situ hybridization showed amplification of murine double minute 2 in 2 cases. Treatments ranged from serial debulking, proton beam irradiation, and exenteration. None of the patients developed metastases. A literature review supported the low-grade nature of this lesion. Orbital atypical lipomatous tumor/well-differentiated liposarcoma is a low-grade, indolent liposarcoma that may be locally invasive. The histologic diagnosis is enhanced with immunohistochemical staining for murine double minute 2 and fluorescent in situ hybridization analysis for amplification of murine double minute 2. Although treatment may vary according to the individual, conservative therapies may be attempted prior to radical surgery.

Orbital Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma Masquerading as Pleomorphic Lipoma: A Diagnostic Challenge

Atypical lipomatous tumor/well-differentiated liposarcoma is a common neoplasm of the superficial and deep soft tissues of the extremities, trunk, and retroperitoneum. Atypical lipomatous tumor/well-differentiated liposarcoma is very rare in the orbit, with only 19 previously reported cases. The authors describe a 22-year-old woman who presented with an 8-month history of diplopia and was found to have an orbital mass on MRI. The excised tumor initially was interpreted as spindle cell/pleomorphic lipoma based on its morphologic and immunohistochemical features. Nine years later, the patient returned with a recurrence that required surgical debulking. Histopathologic and molecular cytogenetic evaluation of both primary and recurrent lesions disclosed Atypical lipomatous tumor/well-differentiated liposarcoma. This case highlights the diagnostic challenges and the importance of molecular genetic studies in evaluation of fatty orbital tumors.

Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma with Myxoid Stroma in a Hereditary Retinoblastoma Survivor

Atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) is an indolent, locally aggressive mesenchymal neoplasm, most often confined to the lower extremities and retroperitoneum and rarely identified in the orbit. Diagnosis of ALT/WDL can be challenging due to its frequent morphologic overlap with benign adipose lesions and other more aggressive liposarcoma subtypes, including myxoid liposarcoma. We describe a 26-year-old female with a history of hereditary retinoblastoma and external-beam radiotherapy to the orbit, who developed orbital liposarcoma. Although initial morphologic assessment raised the consideration of myxoid liposarcoma, subsequent fluorescein in situ hybridization studies demonstrated MDM2 and DDIT3 coamplification without DDIT3 rearrangement, supporting the diagnosis of ALT/WDL with myxoid stroma. The literature review of previously reported orbital myxoid liposarcomas revealed a morphologic overlap of documented tumors with ALT/WDL, dedifferentiated liposarcoma, and pleomorphic liposarcoma with myxoid stroma as well as an absence of immunohistochemical and molecular genetic data supportive of the diagnosis of myxoid liposarcoma. This case emphasizes the potential overlap of ALT/WDL with myxoid liposarcoma and the increasing importance of molecular genetic studies in the diagnosis, prognosis, and management of orbital liposarcoma.

Primary Atypical Lipomatous Tumor of the Orbit: A Case Report

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.

An update on mesenchymal tumours of the orbit with an emphasis on the value of molecular/cytogenetic testing

Mesenchymal tumours of the orbit are uncommon. Beyond childhood primary sarcomas are extremely rare and the literature is limited to case reports and short case series. However there is a diverse assortment of benign and malignant soft tissue tumours that may involve the orbit. Techniques to identify tumour specific cytogenetic or molecular genetic abnormalities often resulting in over- expressed proteins are becoming an increasingly important ancillary technique for these tumours. This review focuses on 3 specific areas: 1. Orbital mesenchymal tumours where cytogenetics are important to reach the correct diagnosis. The majority of these are chromosomal translocations that often result in a fusion gene and protein product; 2. Orbital mesenchymal tumours where cytogenetics are important to identify patients who will do well versus those with a poorer prognosis. This is turn helps with therapeutic options. In some tumours e.g. synovial sarcoma the chromosomal translocations can occur with 2 different regions resulting in different fusion products that carry a different prognosis. Alternatively whilst the majority of alveolar rhadomyosarcomas are fusion positive a minority are fusion negative with a better prognosis; 3. Orbital mesenchymal tumours where the identification of specific cytogenetic abnormalities has resulted in overexpression of specfic proteins which are diagnostically useful biomarkers for immunohistochemistry.

Orbital liposarcoma

CASE REPORT

The case is presented of a 46-year-old male with right eye proptosis and conjunctival hyperaemia, of 18 months onset. A well-defined intraconal mass was found in the computed tomography. In magnetic resonance this was hypo-intense on T1, enhanced with gadolinium and hyperintense on T2. Excisional biopsy was performed, which was reported as a well-differentiated liposarcoma in the histopathology study.

DISCUSSION

Liposarcoma is a malignant adipose tissue tumour. It is very rare in the orbit, with 5 histological types, the most common being myxoid. The treatment of choice is wide surgical excision and may be accompanied with radiotherapy. As it is an infiltrative tumour, It has a high rate of recurrence.

Orbital liposarcoma masquerading as a hemangioma

Liposarcomas are the most common soft tissue sarcomas in adulthood, comprising approximately 20% of all sarcomas; most present in the extremities and retroperitoneum (1). Despite the large amount of adipose tissue in the orbit, orbital liposarcomas are rare. Diagnosis can be challenging due to the rarity of the entity and the pathological similarity to benign adipose tumors (2, 3). Fortunately, the advent of immunohistochemical staining has aided in diagnosis. Management of orbital liposarcoma also can be challenging, as illustrated by the case described herein (4).

Well-differentiated liposarcoma, an atypical lipomatous tumor, of the mesentery: a case report and review of the literature

Mesenteric liposarcoma is a rare neoplasm. Here, we report the case of a 73-year-old Japanese man with a well-differentiated (WD) liposarcoma of the mesentery. Due to rapid growth of the abdominal mass and abdominal insufficiency, a tumorectomy was performed. The excised tumor was 12.4 × 9.6 cm in size and weighed 548 g. Cut sections showed a lobulated yellow and/or grayish-colored appearance. The histological features were predominantly those of the sclerotic and lipoma-like variants of WD liposarcoma. The cytoplasm of most spindle cells was diffusely immunoreactive for CD34, while fat cells were positive for S-100 protein. Some spindle cell nuclei were positive for CDK4, and a few were positive for MDM2. The average Ki-67 proliferation index in tumor cells was 10%, and androgen receptor expression was detected in tumor cell nuclei. The present case and 11 cases identified from a literature search were reviewed. The WD mesenteric liposarcomas developed in patients in the fourth to seventh decades of life (mean age 57.9 years). The patients consisted of 7 men and 5 women. All tumors were larger than 10 cm in diameter at the time of surgery. Complete resection might be the only curative therapy for WD liposarcomas of the mesentery, but long-term follow-up is needed because of the possibility of a local recurrence of the tumor.