Background. Osteosarcomas are typically long bone tumors and rarely affect the skull, with most articles reporting single cases. As elsewhere in the body, these lesions may be classified as primary or secondary, chiefly post‐Paget and post–radiation therapy. Methods. The authors reviewed the osteosarcomas of the skull diagnosed at the Division of Neurosurgery of “La Sapienza” University of Rome. The patients were placed into two groups, according to the treatment received (prechemotherapeutic era and chemotherapeutic era). In the last five patients, a diagnostic‐therapeutic protocol was adopted. Results. The most effective investigations are plain radiographs, computed tomography (CT) with bone windows, and magnetic resonance imaging (MRI), with the latter two allowing assessment of the extraosseous extent of the disease. Chemotherapy has changed the prognosis dramatically, achieving cure in some cases (especially in de novo osteosarcomas). Before the age of chemotherapy, the median survival length was 16 months, but since its introduction, five of nine patients in this study are alive 2 years after diagnosis. The onset of metastases, chiefly to the lung, does not necessarily imply a poor prognosis. The authors propose a schedule for the diagnosis and treatment of new cases of osteosarcoma of the skull. Conclusions. Plain radiographs, CT targeted on the bone, and MRI are the most important diagnostic tools. Aggressive chemotherapy together with surgery (eventually including local radiation therapy in nontotal macroscopic surgical removal of the lesions) can drastically modify the prognosis of de novo and post‐radiation therapy osteosarcomas.

Twenty-eight patients received surgical treatment for a paranasal sinus mucocele with intracranial and/or intraorbital extension. The lesions were classified by site and extension: anterior without intracranial extension (Type 1), 7 patients; anterior with intracranial extension (Type 2), 11 patients; posterior midline without intracranial extension (Type 3), 5 patients; and posterior with intracranial extension (Type 4), 5 patients. The surgical approaches were: transnaso-orbital, transfrontonaso-orbital, transsphenoidal, transmaxillosphenoidal, and subfrontal transbasal; the choice depended on the site and extension of the lesion, with the aim of securing maximum exposure to ensure total removal of the lesion with its capsule. A transcranial approach was reserved for mucoceles possessing an intracranial extension or causing distension of the bone structures with optic pathway neurological symptoms. With a coronal or transfacial skin incision along the lines of the forehead, nose, and orbital muscles of expression and careful reconstruction, the patients' natural cast of features was spared or restored in a single operation.

Intramedullary glioblastomas are uncommon tumors. They occur chiefly in the cervicothoracic segments, have a slight tendency to occur in the early decades of life, and have a short clinical history before diagnosis. We report seven cases and discuss the salient features of these tumors, particularly the pathological features and treatment, in light of the relevant literature.

Intradiploic epidermoid cysts, fairly uncommon lesions in neurosurgical practice, are, as a rule, benign and slow-growing. Some attain great size, producing major neurological signs. Correct radiological assessment and complete removal of the tumour and its capsule are essential for adequate surgical treatment and good long-term prognosis. We report ten cases of intradiploic epidermoid cysts of the skull, three of which were giant lesions and one malignant, and analyze the clinicopathological and radiological features and treatment of these lesions in the light of the most important published data.

The authors report six cases of so-called spinal subdural arachnoid cysts, emphasizing the clinical and myelographic findings which, if not properly evaluated, may be misleading diagnostically. The literature of so-called perineural cysts and of extradural arachnoid cysts is likewise reviewed. Their clinical, roentgenological, and pathological features are examined. A common pathogenesis for all these lesions is proposed. It implies disruption and secondary proliferation of the arachnoid membrane. Hence, the term arachnoid diverticulum is advanced to include all lesions communicating with the subarachnoid space. Their varying relations with the subarachnoid space depend on the sites of the primary abnormalities and on hydrodynamic factors. Numerous observations of associated arachnoid diverticula, either perineural, subdural, or extradural, further favour a common pathogenesis.