Fibro-osseous lesion

Most calvarial lesions arising post-RT are benign and fibro-osseous. Serial imaging is recommended, and high index of suspicion for malignant lesions is warranted for patients genetically predisposed to cancer ¹⁾.

Ossifying fibroma

Cementifying fibroma ²⁾.

Fibrous dysplasia

Calcifying pseudoneoplasms of the neuroaxis

Benign fibro-osseous lesions (BFOLs) are a diverse group of lesions showing considerable degree of overlap with low grade osteosarcoma (LGOS). Further, de-differentiated osteosarcoma (DOS) is usually indistinguishable from conventional high-grade OS (COS) if LGOS foci are not identified. Thus, there is a need for adjunctive immunohistochemical markers to differentiate OS from benign FOLs as well as DOS from COS. A study of Kaur et al. evaluated the role of immunohistochemical expression of MDM2, CDK4, parafibromin, BCL-2 and Galectin-1 (Gal-1) in accurate characterization of benign FOLs and in differentiating them from OS. They retrieved 101 tissue samples which were diagnosed as osteosarcoma (OS) /ossifying fibroma (OF) / fibrous dysplasia (FD) or fibrous hyperplasia (FH) and examined their immunohistochemical staining pattern with the aforementioned antibodies. MDM2 showed 100% specificity for diagnosing OS. CDK4 and Gal-1 showed linear increase in immunoexpression from benign BFOLs to OS. BCL-2 showed equivocal immunopositivity in OF and OS, but the positivity was higher than that observed in FD. The highest immunoexpression for parafibromin was seen in FD followed by OF and OS cases. Thus, MDM2 is most specific, and Gal-1 is most sensitive of all the markers studied in differentiating OS from benign mimics. Combination of these two markers can be used as an adjunct to conventional imaging and microscopy in accurate characterization of these lesions. Further MDM2 overexpression can differentiate DOS and COS. ³⁾.

Giant cell tumor (GCT) of bone is a locally aggressive tumor with low metastatic potential, usually originating in long bones. Numerous spinal examples have been reported and thus GCTs can be encountered by neuropathologists. We describe a 69-year-old man with more than a 10-year history of GCT primary to the femur that had recently metastasized to the occipital skull bone. The patient had been receiving denosumab, an adjuvant therapy for GCT, prior to the metastasis. Review of the histological features of the original primary tumor in the femur showed archetypal features of GCT, but the posttreatment occipital skull metastasis showed a predominantly low-to-medium cell density spindle cell tumor with complete depletion of osteoclastic giant cells. Although this effect of the drug is increasingly being recognized by soft tissue pathologists, the current case illustrates the potentially confusing histology of postdenosumab-treated GCT for neuropathologists. The absence of giant cells leads the posttherapy primary or metastatic lesion to show histologic similarity to a multitude of benign and malignant fibro-osseous lesions or spindle cell sarcoma and highlights the importance of eliciting appropriate clinical history. ⁴⁾.

10: Gauden AJ, Kavar B, Nair SG. Calcifying pseudoneoplasm of the neuraxis: A case report and review of the literature. J Clin Neurosci. 2019 Dec;70:257-259. doi: 10.1016/j.jocn.2019.08.023. Epub 2019 Oct 16. PMID: 31629609.

11: Sturdà C, Rapisarda A, Gessi M, Stifano V, Pompucci A, Anile C, Trevisi G. Bullough's Lesion: An Unexpected Diagnosis After the Resection of a Slowly Growing Osseous-Like Retroauricular Bump-Case Report and Review of the Literature. World Neurosurg. 2019 Feb;122:372-375. doi: 10.1016/j.wneu.2018.11.055. Epub 2018 Nov 15. PMID: 30448575.

12: Ploof J, Shaikh H, Melli J, Jour G, Turtz A. Liposclerosing Myxofibrous Tumor of the Cranial Vault: A Case Report. Neurosurgery. 2019 Mar 1;84(3):E207-E210. doi: 10.1093/neuros/nyy071. PMID: 29538710.

13: Mierzwiński J, Kosowska J, Tyra J, Haber K, Drela M, Paczkowski D, Burduk P. Different clinical presentation and management of temporal bone fibrous dysplasia in children. World J Surg Oncol. 2018 Jan 15;16(1):5. doi: 10.1186/s12957-017-1302-5. PMID: 29335001; PMCID: PMC5769533.

14: Jiang B, Mushlin H, Zhang L, James AW, Cohen AR. Bullough's bump: unusual protuberant fibro-osseous tumor of the temporal bone. Case report. J Neurosurg Pediatr. 2018 Feb;21(2):107-111. doi: 10.3171/2017.8.PEDS17391. Epub 2017 Dec 1. PMID: 29192868.

15: Fadle KN, Hassanein AG, Kasim AK. Orbitocranial Fibrous Dysplasia: Outcome of Radical Resection and Immediate Reconstruction With Titanium Mesh and Pericranial Flap. J Craniofac Surg. 2016 Nov;27(8):e719-e723. doi: 10.1097/SCS.0000000000003033. PMID: 28005795.

16: Belsuzarri TA, Araujo JF, Melro CA, Neves MW, Navarro JN, Brito LG, Pontelli LO, de Abreu Mattos LG, Gonçales TF, Zeviani WM. McCune-Albright syndrome with craniofacial dysplasia: Clinical review and surgical management. Surg Neurol Int. 2016 Mar 11;7(Suppl 6):S165-9. doi: 10.4103/2152-7806.178567. PMID: 27057395; PMCID: PMC4804399.

17: Ciniglio Appiani M, Verillaud B, Bresson D, Sauvaget E, Blancal JP, Guichard JP, Saint Maurice JP, Wassef M, Karligkiotis A, Kania R, Herman P. Ossifying fibromas of the paranasal sinuses: diagnosis and management. Acta Otorhinolaryngol Ital. 2015 Oct;35(5):355-61. doi: 10.14639/0392-100X-533. PMID: 26824919; PMCID: PMC4720932.

18: Alshareef M, Vargas J, Welsh CT, Kalhorn SP. Calcifying Pseudoneoplasm of the Cervicomedullary Junction: Case Report and a Literature Review. World Neurosurg. 2016 Jan;85:364.e11-8. doi: 10.1016/j.wneu.2015.08.055. Epub 2015 Sep 1. PMID: 26341436.

19: Stapleton AL, Tyler-Kabara EC, Gardner PA, Snyderman CH. Endoscopic endonasal surgery for benign fibro-osseous lesions of the pediatric skull base. Laryngoscope. 2015 Sep;125(9):2199-203. doi: 10.1002/lary.25070. Epub 2015 Jun 24. PMID: 26108687.

20: Park B, Abode-Iyamah K, Lee SL, Kirby P, El-Khoury G, Wilson S. Fibro- osseous lesion of the cranium in an adolescent patient. Surg Neurol Int. 2015 Jan 22;6:12. doi: 10.4103/2152-7806.149848. PMID: 25657865; PMCID: PMC4310058.

21: Sanchez Burgos R, González Martín-Moro J, Arias Gallo J, Carceller Benito F, Burgueño García M. Giant osteoma of the ethmoid sinus with orbital extension: craniofacial approach and orbital reconstruction. Acta Otorhinolaryngol Ital. 2013 Dec;33(6):431-4. PMID: 24376302; PMCID: PMC3870443.

22: Nonaka Y, Aliabadi HR, Friedman AH, Odere FG, Fukushima T. Calcifying pseudoneoplasms of the skull base presenting with cranial neuropathies: case report and literature review. J Neurol Surg Rep. 2012 Oct;73(1):41-7. doi: 10.1055/s-0032-1321503. Epub 2012 Jul 2. PMID: 23946925; PMCID: PMC3658655.

23: Rowland NC, Jermakowicz WJ, Tihan T, El-Sayed IH, McDermott MW. Subacute cystic expansion of intracranial juvenile psammomatoid ossifying fibroma. J Neurosurg Pediatr. 2013 Jun;11(6):687-91. doi: 10.3171/2013.2.PEDS12253. Epub 2013 Mar 29. PMID: 23540525.

24: Anik I, Koc K, Cabuk B, Ceylan S. Endoscopic transphenoidal approach for fibrous dysplasia of clivus, tuberculum sellae and sphenoid sinus; report of three cases. Turk Neurosurg. 2012;22(5):662-6. doi: 10.5137/1019-5149.JTN.4060-10.0. PMID: 23015349.

25: Linhares P, Pires E, Carvalho B, Vaz R. Juvenile psammomatoid ossifying fibroma of the orbit and paranasal sinuses. A case report. Acta Neurochir (Wien). 2011 Oct;153(10):1983-8. doi: 10.1007/s00701-011-1115-1. Epub 2011 Aug 10. PMID: 21826543.

26: Borkar SA, Kasliwal MK, Sinha S, Sharma BS. MR imaging in aneurysmal bone cyst of the orbit. Turk Neurosurg. 2008 Apr;18(2):183-6. PMID: 18597234.

27: Westendorff C, Hoffmann J, Troitzsch D, Dammann F, Reinert S. Ossifying fibroma of the skull: interactive image-guided minimally invasive localization and resection. J Craniofac Surg. 2004 Sep;15(5):854-8. doi: 10.1097/00001665-200409000-00029. PMID: 15346031.

28: Cernea CR, Teixeira GV, Medina dos Santos LR, Vellutini EA, Siqueira MG. Indications for, contraindications to, and interruption of craniofacial procedures. Ann Otol Rhinol Laryngol. 1997 Nov;106(11):927-33. doi: 10.1177/000348949710601108. PMID: 9373083.

29: Nakagawa K, Takasato Y, Ito Y, Yamada K. Ossifying fibroma involving the paranasal sinuses, orbit, and anterior cranial fossa: case report. Neurosurgery. 1995 Jun;36(6):1192-5. doi: 10.1227/00006123-199506000-00021. PMID: 7644003.

30: Shose Y, Nogaki H, Kurihara E. [Ossifying fibroma of the cranial vault. Case report]. Neurol Med Chir (Tokyo). 1990;30(11 Spec No):879-83. Japanese. doi: 10.2176/nmc.30.879. PMID: 1709469.