2024-Case 9

by | Sep 15, 2024 | 2024 Diagnostic Case Studies

Presenter

Shervin Pejhan

Authors

Shervin Pejhan1, Ryan Wang2, Sachin Pandey3, Joseph Megyesi2, Claire Coire4, Lee Cyn Ang1,2

1 Department of Pathology & Lab Medicine, Western University, ON, Canada

2 Department of Clinical Neurological Sciences, Western University, ON, Canada

3 Department of Medical Imaging, Western University, ON, Canada

4 Department of Pathology, Trillium Health Partners, Mississauga Hospital, ON, Canada

Conflict of Interest

I do not have a relationship with a for-profit and/or a not-for-profit organization to disclose.

Clinical Summary

A 76-year-old gentleman presented to the hospital with nausea, and vomiting, after his diabetes medication was switched from Empagliflozin to metformin. He had also a worsening gait instability for more than a year, and a coincidental headache during that admission that ended up in a CT-head which showed a mass in the 4th ventricle without obstructive hydrocephalus. His past medical history was curious for a low-grade prostatic adenocarcinoma (stage pT1a), diagnosed by TURP more than 4 years ago, left lower lung lobectomy of unknown reason in 2011, and a spinal tumor resected in 2002. The MRI showed a T2 weighted hyperintense mass centered in the 4th ventricle (2.9 x 2.9 x 2.5 cm). The lesion demonstrated heterogeneous enhancement, with apparent solid and cystic components. He underwent suboccipital craniectomy and resection of the 4th ventricular mass.

Discussion points

  1. What are the differential diagnoses for this lesion?

  2. What special stains, IHCs, or ancillary testing would be most informative?

MR images
H&E-stained slide
H&E-stained smear
Reveal Diagnosis

Epithelioid solitary fibrous tumor, at least CNS WHO grade 2

Additional relevant investigations and comment.
The diagnosis of the spinal tumor resected and radiated in 2002 was malignant hemangiopericytoma. The slides were collected and reviewed. Immunostaining for STAT-6 confirmed the diagnosis. The location of current tumor (intraventricular) is uncommon for a relatively rare subtype of SFT (epithelioid). SFT is known for recurrence and metastasis long time after the initial diagnosis. However, it cannot be determined if this tumor was a second primary or a metastatic SFT from the primary spinal tumor in 2002.

References
1. Macagno N, Vogels R, Appay R, et al. Grading of meningeal solitary fibrous tumors/hemangiopericytomas: analysis of the
prognostic value of the Marseille Grading System in a cohort of 132 patients. Brain Pathol. 2019;29(1):18-27.
2. Fritchie K, Jensch K, Moskalev EA, et al. The impact of histopathology and NAB2-STAT6 fusion subtype in classification and
grading of meningeal solitary fibrous tumor/hemangiopericytoma. Acta Neuropathol. 2019;137(2):307-319.
3. Fritchie KJ, Jin L, Rubin BP, et al. NAB2-STAT6 Gene Fusion in Meningeal Hemangiopericytoma and Solitary Fibrous Tumor.
J Neuropathol Exp Neurol. 2016;75(3):263-71.
4. Fu J, Zhang R, Zhang H, et al. Epithelioid solitary fibrous tumor of the central nervous system. Clin Neurol Neurosurg.
2012;114(1):72-6.
5. Suster DI, Mackinnon AC, Mejbel HA, et al. Epithelioid and Clear Cell Solitary Fibrous Tumors: Clinicopathologic,
Immunohistochemical, and Molecular Genetic Study of 13 Cases. Am J Surg Pathol. 2023 1;47(2):259-269.
6. Tariq MU, Asghari T, Armstrong SM, et al. Solitary fibrous tumor of head and neck region; A clinicopathological study of 67
cases emphasizing the diversity of histological features and utility of various risk stratification models. Pathol Res Pract.
2023;249.

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