Stroke in a child with cutaneous naevi: a diagnostic trail toward suspected cavernoma-associated phakomatosis with histologic discordance and early multicentric recurrence-adjuvant therapeutic implications.

BACKGROUND: Phakomatoses, also known as neurocutaneous syndromes are rare disorders characterized by multisystem involvement with variable neurological manifestations in children, including intracranial vascular malformations. Cavernous malformations may present with acute haemorrhage and stroke-like symptoms. Diagnostic difficulty arises when radiologic findings suggest a benign lesion, yet histopathology reveals discordant malignant pathology. CASE PRESENTATION: An 8-year-old female presented with sudden-onset left hemiparesis and recurrent seizures. Physical examination revealed multiple cutaneous naevi, raising suspicion of a syndromic association. Brain magnetic resonance imaging demonstrated a well-circumscribed right parietal intra-axial lesion with a "popcorn" appearance and hypointense susceptibility blooming, highly suggestive of a cavernous malformation. Cranial computed tomography scan subsequently showed an associated large intracerebral haematoma. The patient underwent right parietal craniotomy with haematoma evacuation and excision of the lesion. The immediate postoperative course was initially satisfactory with neurological improvement. Histopathological examination of the excised specimen, however, revealed a malignant neoplasm, establishing a significant radiologic-histologic discordance which fundamentally altered the diagnostic interpretation. The patient had a relapse of symptoms two months after surgery, with repeat neuroimaging showing multicentric tumour recurrence, necessitating referral for adjuvant neuro-oncologic management. CONCLUSION: This case illustrates a rare diagnostic pitfall and challenge in paediatric neurosurgery, where a malignant intracranial tumour mimicked a cavernous malformation in the context of cutaneous stigmata. The report emphasizes the limitations of neuroimaging alone and underscores the importance of careful clinicoradiologic correlation, histopathological confirmation, and multidisciplinary evaluation when managing presumed vascular lesions in children, particularly in resource-limited settings.