Angioleiomyoma of the falx

Intracranial angioleiomyoma: a case series of seven patients and review of the literature

PURPOSE

Angioleiomyoma, predominantly arising from the extremities, is a benign soft tissue tumor. Reports on its intracranial location are rare. We assessed clinical, radiological, and pathological features of intracranial angioleiomyoma (iALM) treated at our neurosurgical institution.

METHODS

We consecutively enrolled all patients with neuropathologically confirmed iALM treated at a single neurosurgical institution between 2013 and 2021. Clinical and imaging data were collected, and histological tissue sections were analyzed. A review of the literature on iALM was conducted.

RESULTS

Seven patients with iALM (four female) with a median age of 45 years (range: 32-76 years) were identified. In three cases, the lesion was found incidentally. In magnetic resonance imaging (MRI), all tumors were hypo- to isointense on T1-weighted, hyperintense on T2-weighted sequences, and gadolinium-enhancing. A strong FLAIR signal was seen in six patients. Surgery consisted of gross total resection in all cases without perioperative complications. Neuropathological staining was positive for smooth muscle actin (SMA) in all lesions. Mature smooth muscle cells arranged around blood vessels were typically observed. The Ki-67 index was ≤ 3%. The patients were discharged after a median of 6 days (range: 4-9 days). During a median follow-up time of 14 months (range: 4-41 months), no tumor recurrence occurred. In the current literature, 42 additional cases of iALM were identified.

CONCLUSION

Intracranial angioleiomyoma is a benign soft tissue tumor treated by gross total resection. Tumor morphology and positive staining for SMA lead to the neuropathological diagnosis.

The dural angioleiomyoma harbors frequent GJA4 mutation and a distinct DNA methylation profile

The International Society for the Study of Vascular Anomalies (ISSVA) has defined four vascular lesions in the central nervous system (CNS): arteriovenous malformations, cavernous angiomas (also known as cerebral cavernous malformations), venous malformations, and telangiectasias. From a retrospective central radiological and histopathological review of 202 CNS vascular lesions, we identified three cases of unclassified vascular lesions. Interestingly, they shared the same radiological and histopathological features evoking the cavernous subtype of angioleiomyomas described in the soft tissue. We grouped them together with four additional similar cases from our clinicopathological network and performed combined molecular analyses. In addition, cases were compared with a cohort of 5 soft tissue angioleiomyomas. Three out 6 CNS lesions presented the same p.Gly41Cys GJA4 mutation recently reported in hepatic hemangiomas and cutaneous venous malformations and found in 4/5 soft tissue angioleiomyomas of our cohort with available data. Most DNA methylation profiles were not classifiable using the CNS brain tumor (version 12.5), and sarcoma (version 12.2) classifiers. However, using unsupervised t-SNE analysis and hierarchical clustering analysis, 5 of the 6 lesions grouped together and formed a distinct epigenetic group, separated from the clusters of soft tissue angioleiomyomas, other vascular tumors, inflammatory myofibroblastic tumors and meningiomas. Our extensive literature review identified several cases similar to these lesions, with a wide variety of denominations. Based on radiological and histomolecular findings, we suggest the new terminology of "dural angioleiomyomas" (DALM) to designate these lesions characterized by a distinct DNA methylation pattern and frequent GJA4 mutations.

Atypical localization of intraosseous angioleiomyoma in the rib of a pediatric patient: a case report

BACKGROUND

This is the first reported case of a primary intraosseous angioleiomyoma and the second case of a primary leiomyoma of the rib, irrespective of age. Angioleiomyomas mostly occur in patients of advanced age, in any part of the body, particularly the lower extremities and present as painful, slow-growing nodules in the dermis, subcutaneous fat or deep fascia. Other localizations, especially bone, are considered extremely rare, as well as their occurrence in paediatric patients.

CASE PRESENTATION

A 10-year-old girl was admitted to the orthopaedic surgery department for further assessment of a pain localized in the posterior part of the right hemithorax. After magnetic resonance imaging (MRI) and surgical biopsy, intraosseus angioleiomyoma of the fourth rib was diagnosed by histopathology examination. Atypical costal localization of this type of a benign tumour presents diagnostic difficulty, especially in children. The differential diagnoses included cartilaginous tumours, Ewing sarcoma, fibrous dysplasia, Langerhans cell histiocytosis, intraosseous haemangioma and metastatic tumours. We report a detailed diagnostic procedure including MRI, selective angiography and histopathologic examination.

CONCLUSION

Diagnosis of intraosseous angioleiomyoma is difficult due to the extreme rarity of this tumour and absence of pathognomonic radiological signs. Although very rarely identified in bones and young age group, radiographers and reporting doctors should be aware of this possible angioleiomyoma presentation and supported by the provided detailed diagnostic information.