Rare Skull Tumors Diagnosed in Three Patients After Mimicking Other Bone Diseases

Surgeons and pathologists in India have described three patients, including two children, who were treated for primary intraosseous cavernous hemangioma of the skull, a rare benign vascular tumor that arises within bone itself. The case series, published in the Egyptian Journal of Neurosurgery, reports that in all three patients the initial radiological impression pointed toward other calvarial lesions, such as eosinophilic granuloma or fibrous dysplasia, and that the true diagnosis was only established after the lesions were excised and examined under the microscope.

Primary intraosseous cavernous hemangiomas, abbreviated PICHs, are vascular hamartomas that arise within bone. According to the paper, they account for 0.7 to 1.0 percent of all bone tumors and are generally seen in adults, with most patients presenting during the fourth to sixth decades of life. They usually occur in the vertebral column and are rarely seen in the skull, where the frontal bone is most commonly involved, followed by the parietal, temporal and, less frequently, the occipital bone. The earliest description of a skull PICH dates to 1845, and the authors note that about 100 cases of cranial primary intraosseous cavernous hemangioma have been described in the literature. A dedicated review of pediatric cranial intraosseous hemangiomas identified only 24 pediatric cases aged 18 years or younger, of all histologic types, underscoring how uncommon these lesions are in children. Cranial PICHs demonstrate a female predominance, and in the largest systematic review to date, encompassing 77 patients, the female-to-male ratio was 1.4:1 with a mean age of 32.7 years.

The first patient in the series was a 12-year-old girl who presented with headache and progressive proptosis of the right eye of one year’s duration. She had no past history of trauma to the head or eye. A CT scan showed expansion of the greater wing of the sphenoid bone with ground-glass haziness, and MRI revealed a lesion measuring 5 by 2 by 2 centimeters causing mass effect and proptosis. The radiological impression was of an eosinophilic granuloma or fibrous dysplasia. She underwent a right pterional craniotomy with total excision of the hyperostotic and dysplastic bone together with a margin of surrounding normal bone. Intraoperatively, the lesion was highly vascular, discoloured and bluish to purple in colour, while the dura and periorbital fat were uninvolved. Histopathological examination demonstrated a vascular lesion composed of large thin-walled vessels infiltrating the bone with areas of hemorrhage, consistent with an intraosseous cavernous hemangioma. Three months after surgery, a 3D CT scan was used to design a patient-specific hydroxyapatite-coated titanium mesh implant for delayed cranioplasty, and at four years of follow-up the patient is doing well with no recurrence.

The second patient was a 9-year-old girl who presented with pain and a gradually increasing swelling on the right side of the forehead. The swelling was soft and fluctuant on examination. CT of the head demonstrated an expansile lesion involving the frontal bone with a characteristic sunburst appearance. She underwent a right frontal craniotomy and excision of the lesion, which was moderately vascular, followed by on-table titanium mesh cranioplasty with hydroxyapatite coating. The excised lesion was expansile, involving the frontal bone and measuring 5 by 5 by 3 centimeters, globular and dark red to brown in colour on gross examination, with a firm to hard cut section containing hemorrhagic and small cystic spaces ranging from 0.2 to 1 centimeter. Histopathology confirmed an intraosseous cavernous hemangioma. At two years of follow-up she is doing well, with no evidence of recurrence.

The third patient was a 22-year-old man who presented with proptosis of the left eye over the past two years and no history of head trauma. The mass was stony hard and tender and measured approximately 10 by 7 centimeters. A plain skull X-ray showed an expansive lesion of the skull bone, and CT showed hyperostosis of the left frontal bone and orbital roof, the medial aspect of the orbit, and an irregular lytic lesion. Radiology reported the mass as fibrous dysplasia. A near-total excision was accomplished, with the portion involving the medial orbital aspect intentionally left in place to avoid cosmetic deformity. The lesion was vascular and hyperostotic. Gross examination showed a hyperostotic frontal bone measuring 10 by 7 by 2 centimeters with a grey-white, stony-hard cut section, and histopathology demonstrated an intraosseous cavernous hemangioma. Six months after surgery, a 3D CT scan was used to design a patient-specific hydroxyapatite-coated titanium mesh implant for delayed cranioplasty, and at one year of follow-up the patient is doing well with no further growth of the lesion.

The imaging findings in these cases illustrate why preoperative diagnosis of skull PICHs is so difficult. Plain radiographs typically show a well-circumscribed osteolytic, intradiploic lesion with expansion of the diploic space and thinning and expansion of the inner and outer tables, with radiating trabeculae producing the classic sunburst or sun-ray appearance, or a honeycomb appearance when the trabeculae are coarser and interlacing. Cortical destruction is usually absent, although marked thinning or focal cortical breach can occur in larger lesions, and there may occasionally be soft-tissue extension. On CT, thickened vertical trabeculation is better visualized, with a honeycomb or sunburst pattern of fine, radiating and reticulated trabeculae. MRI shows intermediate to high T1 signal intensity and high heterogeneous T2 signal intensity, and is described as the ideal modality for demonstrating mass-effect complications such as neural impingement and extraosseous extension. In the present series, the first case showed a ground-glass appearance of the sphenoid wing that is classic for fibrous dysplasia, a location where PICH is exceptionally rare; the second case’s sunburst appearance was weighed against the patient’s young age, which made eosinophilic granuloma and other pediatric calvarial lesions important considerations; and the third case showed diffuse hyperostosis with orbital involvement, a well-recognized imaging pattern of fibrous dysplasia and intraosseous meningioma, explaining the initial radiological interpretation.

Under the microscope, intraosseous hemangiomas demonstrate hamartomatous vascular tissue within endothelium, and may also contain fat, smooth muscle, fibrous tissue and thrombi. They exhibit blood-filled vascular channels lined by a single layer of flattened endothelial cells that are small, monolayered and lack cytologic atypia, separated by scant connective-tissue stroma within bony trabeculae. On the basis of the size of the vascular spaces and the amount of connective tissue, three histological subtypes have been described: cavernous, capillary and mixed. Most intraosseous hemangiomas are of the cavernous type, characterized by clusters of dilated, large thin-walled vessels and sinuses separated by fibrous septa. All three cases in this series were of the cavernous type and displayed dilated vessels lined by thin endothelial cells, focally congested, with areas of hemorrhage. The authors emphasize that histopathological examination is often necessary to confirm the diagnosis, because preoperative diagnosis of cavernous hemangiomas is often difficult since imaging findings are not specific.

The differential diagnosis for intraosseous hemangioma is broad, and the paper lists arteriovenous malformation, intraosseous meningioma, aneurysmal bone cyst, fibrous dysplasia, osteoma, Langerhans cell histiocytosis, dermoid tumor, multiple myeloma and metastasis. In hemangiomas, microscopic examination shows many dilated, thin-walled vascular spaces lined by benign endothelial cells and containing large numbers of red blood cells, with fibrous connective tissue stroma supporting the spaces among the trabeculae. The presence of arteries, arterioles, or both as an integral part of the lesion, as shown by elastic tissue stains, is often used as a criterion for differentiating arteriovenous malformations from hemangiomas. The pathogenesis of PICH remains unknown, although a history of trauma has been implicated in some cases, and recent studies have reported that trauma and ionizing radiation, particularly stereotactic radiosurgery for brain tumors, may be related to the development of hemangiomas of the skull. Some researchers have proposed that cavernous hemangioma may be an inherited disease, with a mutation in the KRIT1/CCM1 gene, which encodes a protein affecting endothelial cell structure and function, implicated in pathogenic mechanisms. The authors note that the genetics of their cases was not evaluated, and that a congenital intraosseous cavernous hemangioma of the skull was previously reported from their institution, suggesting these lesions may rarely present in the congenital period even though their precise pathogenesis remains uncertain.

Regarding management, the paper states that treatment is reserved for symptomatic lesions and that options may include embolization to reduce intraoperative blood loss, surgical resection, intralesional ethanol injection and radiation therapy. Complete resection by craniectomy, including a healthy bone margin, is described as the treatment of choice with excellent prognosis, and recurrence is usually rare. For a single mass, complete resection with primary reconstruction using an autologous bone graft is the preferred method because it reduces morbidity and usually yields satisfactory cosmetic results. If the lesion is relatively large, embolization followed by excision is desirable, while multiple lesions may require combined radiotherapy, particularly for diffuse cranial hemangiomas.

The authors are candid about the limitations of their work. The study is a retrospective, single-center case series comprising only three patients, reflecting the rarity of primary intraosseous cavernous hemangioma, and the findings cannot be generalized or used to establish definitive diagnostic or therapeutic recommendations. Preoperative diagnosis relied primarily on conventional imaging, advanced vascular imaging was not uniformly available, and histopathological examination remained the gold standard for diagnosis. The absence of a comparative cohort and the relatively limited follow-up restrict assessment of long-term outcomes and recurrence. Even so, the series adds to the limited published experience with this entity in children, describing two pediatric patients with frontal and sphenoid involvement and highlighting both the diagnostic challenges posed by overlapping radiological features and the successful surgical management of this rare benign tumor.

Subject of Research: Primary intraosseous cavernous hemangioma of the skull

Article Title: A case series of primary intraosseous cavernous hemangioma of the skull

Article References: Batool, S., Makhdoomi, R., Abeer, I., Zargar, M., Syed, S., & Malik, N. (2026). A case series of primary intraosseous cavernous hemangioma of the skull. Egyptian Journal of Neurosurgery, 41(1), Article 180. https://doi.org/10.1186/s41984-026-00667-y

Image Credits: AI Generated

DOI: 10.1186/s41984-026-00667-y

Keywords: cavernous hemangioma, skull tumor, intraosseous lesion, case series, pediatric neurosurgery, cranioplasty, histopathology, calvarial tumors, fibrous dysplasia, surgical excision, neurosurgery, rare disease