Figure 1. Axial (A) and coronal (B) computed tomographic images demonstrating a left 2.7 × 1.7 × 1.6-cm mass isodense to muscle (A) and with homogeneous intense contrast enhancement (B).
Figure 2. Gross tumor following excision.
Figure 3. Short intersecting fascicles of cytologically bland spindle cells arranged in a “patternless pattern” (hematoxylin-eosin) (A), dilated hemangiopericytic thin-walled vessels (hematoxylin-eosin) (B), and positive CD34 immunostaining (C) (original magnification ×200).
Griepentrog GJ, Harris GJ, Zambrano EV. Multiply Recurrent Solitary Fibrous Tumor of the Orbit Without Malignant Degeneration: A 45-Year Clinicopathologic Case Study. JAMA Ophthalmol. 2013;131(2):265-267. doi:10.1001/2013.jamaophthalmol.69
Author Affiliations: Section of Oculofacial and Orbital Surgery, Department of Ophthalmology (Drs Griepentrog and Harris) and Section of Musculoskeletal Pathology, Department of Pathology (Dr Zambrano), Medical College of Wisconsin, Milwaukee.
Solitary fibrous tumor (SFT) is a rare mesenchymal spindle cell neoplasm originally described in the pleura and subsequently identified in a number of extrathoracic sites. Orbital SFT was first described in 1994; since then, more than 100 cases have been reported or reclassified with that diagnosis.1,2 Only 4 patients were younger than 10 years when first diagnosed as having orbital SFT. While most reports describe a benign clinical course, rare cases of primary malignant orbital SFT have also been documented. This led the World Health Organization to classify SFT as a neoplasm of intermediate biological potential (locally aggressive, rarely metastasizing).3,4 Increased cellular atypia or mitotic activity in recurrent lesions following primary excision of orbital SFTs has also been described, suggesting that complete initial resection is a critical prognostic factor in preventing malignant degeneration.1,4- 7 We describe a patient with orbital SFT whose proptosis was first recognized at age 9 years and who underwent surgical excision at various institutions at ages 12, 22, and 52 years. To our knowledge, this represents the longest histopathologically documented follow-up of a patient with orbital SFT.
In 1967, a 9-year-old girl with painless left proptosis underwent an exploratory craniotomy in which no tumor was found. With a presumptive diagnosis of orbital hemangioma, she was treated with external beam radiation. In 1970, she underwent an orbitotomy with removal of a 4.0 × 2.5-cm lobulated, reddish-blue mass, described as a hemangioma. Recurrent proptosis was noted in 1980, and a lateral orbitotomy with bone flap was performed with removal of a 5-cm lesion. At that time, review at the Armed Forces Institute of Pathology of the 1970 and 1980 specimens yielded a diagnosis of fibrous histiocytoma.
In 2010, the patient was referred to our institution with a history of gradually recurrent proptosis and recent-onset diplopia. Orbital imaging demonstrated a large, homogeneously enhancing mass that filled the inferotemporal extraconal and intraconal left orbit (Figure 1). A lower fornix-approach orbitotomy was performed with removal of all gross tumor (Figure 2). Histologic sections showed a proliferation of spindle cells with eosinophilic cytoplasm, poorly defined cytoplasmic borders, and elongated nuclei with small eosinophilic nucleoli, arranged in short intersecting fascicles in a “patternless pattern” (Figure 3A). Occasional hemangiopericytic thin-walled vessels were present (Figure 3B). Rare mitotic figures were seen, with no atypical forms, areas of necrosis, or cytologic atypia identified. Immunohistochemical staining revealed that neoplastic cells were strongly and diffusely positive for CD34 (Figure 3C), CD99, and Bcl-2 and negative for smooth muscle actin, muscle-specific actin, desmin, S-100 protein, and AE1/AE3 cytokeratins, supporting the diagnosis of SFT. The patient did well following gross tumor excision and remained symptom free at 1 year.
We are aware of 4 cases of recurrent SFT that showed increased cellularity, atypia, or mitotic rate compared with the primary lesions, suggesting malignant transformation with time.4- 7 Such cases have led to the conclusion that the most important prognostic factor is not the initial histologic appearance but rather complete primary resection.1 In those reports, the interval between initial tumor excision and final recurrent tumor excision ranged from 6 months to 7 years. Our case provides further insight into the heterogeneous histologic and clinical behavior of these tumors. After an interval that included initial recognition of proptosis at age 9 years and multiple surgical resections as late as age 52 years, there were no histopathologic features to suggest malignant transformation. A limitation of this study is that the 1970 and 1980 outside histopathologic material is no longer available to document a uniform diagnosis throughout the 45-year course. However, a 1980 Armed Forces Institute of Pathology review of that material did yield a diagnosis of orbital fibrous histiocytoma, an entity that has been more recently reclassified as orbital SFT in many cases.2 Our case suggests that incompletely excised, long-standing SFTs do not necessarily increase in biological aggressiveness.
Correspondence: Dr Griepentrog, Section of Oculofacial and Orbital Surgery, Department of Ophthalmology, Medical College of Wisconsin, 925 N 87th St, Milwaukee, WI 53226 (firstname.lastname@example.org).
Author Contributions: Drs Griepentrog and Harris had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported in part by an unrestricted grant from Research to Prevent Blindness.