Pituitary metastasis of salivary gland carcinoma mimicking hypophysitis: A case report and literature review.

INTRODUCTION: Pituitary metastases from salivary gland carcinomas are rare. Moreover, pituitary metastasis and hypophysitis exhibit neuroimaging similarities that complicate the diagnosis in patients receiving immune checkpoint drugs. PRESENTATION OF CASE: We present a case of pituitary metastasis derived from a sublingual gland carcinoma; this case posed a challenge in the differential diagnosis of hypophysitis. A 52-year-old male patient presented with anorexia and visual disturbances. The patient was previously diagnosed with sublingual gland carcinoma that necessitated surgical intervention consisting of tumor resection and residual lymph node dissection. Subsequently, the patient underwent immune checkpoint blockade therapy following platinum-based chemotherapy. Magnetic resonance imaging revealed the presence of an intrasellar tumor infiltrating the dura mater, cavernous sinus, and pituitary stalk with isointensity on T1 and T2 weighted images and homogeneous gadolinium enhancement. Despite the initial suspicion of hypophysitis, diagnostic treatment with systemic corticosteroids failed to induce significant tumor reduction. Diagnostic clarification was achieved via an endoscopic transsphenoidal biopsy, which confirmed the histological diagnosis of pituitary metastasis from the prior sublingual gland adenocarcinoma. Radiotherapy was administered as a therapeutic intervention. DISCUSSION: The case report highlighted the rarity of metastases from salivary gland carcinoma to the pituitary gland and emphasized the challenges in distinguishing between pituitary metastasis and hypophysitis based on imaging studies alone, particularly in patients receiving immune checkpoint inhibitors. CONCLUSION: Given the rarity of this condition and its neuroimaging similarities with hypophysitis, pathological confirmation is imperative for a definitive diagnosis.

Impact of Morphological Factors on the Future Growth of Unruptured Posterior Communicating Artery Aneurysms.

BACKGROUND: No previous study has established the factors associated with intracranial aneurysm growth using imaging data obtained before the appearance of morphological changes. Therefore, we investigated the factors related to future aneurysm growth in posterior communicating artery (Pcom) aneurysms. METHODS: Using a longitudinal database of intracranial aneurysm cases, we reviewed the findings for consecutive patients with unruptured Pcom aneurysms admitted to our institute from 2012 to 2021. Magnetic resonance images obtained over time were used to evaluate aneurysm growth. Aneurysms showing growth over time (group G) and unchanged aneurysms (group U) were compared in terms of background data and morphological factors. RESULTS: 93 Pcom aneurysms (group G: 25 aneurysms, 25%; group U: 68 aneurysms, 75%) were eligible for the present study. Six aneurysm rupture events occurred in group G (24%). Among morphological factors, Pcom diameter (1.2 ± 0.3 mm vs. 0.8 ± 0.7 mm, P < 0.01), bleb formation (group G: 39% vs. group U: 10%; odds ratio, 5.6; P = 0.01), and the lateral projection of the dome (group G: 52% vs. group U: 13%; odds ratio, 3.2; P = 0.023) were significantly different between the 2 groups. The sensitivity and specificity of a cutoff Pcom diameter of 0.73 mm for predicting enlargement were 96% and 53%, respectively. CONCLUSIONS: Pcom diameter, bleb formation, and lateral dome projection were associated with growth of Pcom aneurysms. Aneurysms with these risk factors require careful follow-up imaging, which may facilitate early detection of aneurysm growth and prevention of rupture through therapeutic interventions.

Spinal cord astroblastoma with EWSR1-BEND2 fusion classified as HGNET-MN1 by methylation classification: a case report.

The most recurrent fusion of central nervous system high-grade neuroepithelial tumor with MN1 alteration (HGNET-MN1) is MN1 rearrangement. Here, we report the case of a 36-year-old man with spinal cord astroblastoma showing Ewing Sarcoma breakpoint region 1/EWS RNA-binding protein 1 (EWSR1)-BEN domain-containing 2 (BEND2) fusion. The patient presented with back pain, gait disturbance and dysesthesia in the lower extremities and trunk. Magnetic resonance imaging showed an intramedullary tumor at the T3-5 level, displaying homogeneous gadolinium enhancement. Partial tumor removal was performed with laminectomy. Histological examinations demonstrated solid growth of epithelioid tumor cells showing high cellularity, a pseudopapillary structure, intervening hyalinized fibrous stroma, and some mitoses. Astroblastoma was diagnosed, classified as HGNET-MN1 by the German Cancer Research Center methylation classifier. MN1 alteration was not detected by fluorescence in situ hybridization (FISH), but EWSR1-BEND2 fusion was detected by FISH and RNA sequencing. Previously, a child with EWSR1-BEND2 fusion-positive spinal astroblastoma classified as HGNET-MN1 was reported. In conjunction with that, the present case provides evidence that EWSR1-BEND2 fusion is identified in the entity of HGNET-MN1. Taken together, the BEND2 alteration rather than MN1 may determine the biology of a subset of the central nervous system HGNET-MN1 subclass.

A Rare Case of Schwannoma Arising from the Dura Mater of the Petrosal Surface in the Posterior Cranial Fossa.

BACKGROUND: An intracranial schwannoma originating in the dura mater is extremely rare. Herein, we report a case of schwannoma arising from the dura mater of the petrosal surface in the posterior cranial fossa. CASE DESCRIPTION: A 48-year-old man presented with slight gait disturbance and papilledema. Magnetic resonance imaging showed a T1- and T2-weighted mixed-intensity extra-axial tumor, approximately 4 cm in the maximum diameter with multiple small cysts, in the left posterior cranial fossa. The tumor was heterogeneously enhanced with gadolinium. Operative findings via a lateral suboccipital approach revealed that the tumor did not adhere to any cranial nerves but to the dura mater of the petrosal surface. The tumor was completely excised without any neurologic deficits, and the histologic diagnosis was schwannoma. CONCLUSIONS: The operative and postoperative findings suggested that the schwannoma originated in the meningeal branch of the lower cranial nerves or upper cervical nerves in the dura mater of the petrosal surface in the posterior cranial fossa.