CASE 15740 Published on 27.05.2018

Pituitary macroadenoma with perineural extension

Section

Head & neck imaging

Case Type

Clinical Cases

Authors

Cayetano Sempere Ortega.

Mahmoud Shahin.

Juan Martinez San Millan.

Hospital Ramon y Cajal; Carretera Colmenar km 9100 28034 Madrid, Spain; Email:csempereortega@gmail.com.

ERESA Grupo Médico, Valencia, Spain.
Patient

65 years, male

Categories
Area of Interest Head and neck ; Imaging Technique CT, MR
Clinical History

A previously healthy 65-year-old male patient presented to the emergency room with a three-day history of headache, nausea and vomiting. On examination he showed normoreactive and isochoric pupils, left ptosis, complete paresis of the III and IV left cranial nerves and partial paresis of the right IV. No campimetric defects were observed.

Imaging Findings

Emergency cranial CT was performed. CT images showed an expansive intrasellar mass with invasion of the left cavernous sinus (Fig. 1). The sella turcica was enlarged and there was no destruction of its osseous boundaries. A discrete suprasellar extension was observed (Fig. 2).
MRI was also performed prior to urgent surgical decompression. T1-weighted images after administration of contrast showed high signal foci inside the mass due to the presence of blood (Fig. 3). T2-weighted images demonstrated extension to the Meckel's cave (Fig. 4, 5). Post-contrast images in coronal and axial planes also demonstrated enlargement and intense enhancement of the left trigeminal nerve along its cisternal portion (Fig. 6, 7).

Discussion

Cranial nerves could be involved in different benign and malignant neoplastic lesions [1]. Among the former, infection, inflammatory pseudo-tumour and granulomatous disease are the most common causes [2]. The most common primary tumour is schwannoma constituting about 85%. Secondary involvement could be due to direct extension from the surrounding tumours, perineural spread or haematogenous metastasis [3].

Perineural spread through cranial nerves is a well-recognised phenomenon in head and neck cancers. It was first described in 1835 [4]. It is related to poor prognosis and treatment failure due to incomplete tumour resection. The most common histological types associated with perineural spread are squamous cell carcinoma [5], salivary gland neoplasms (adenoid cystic [6] and mucoepidermoid carcinomas), melanoma and lymphoma [3]. Meningioma and nasopharyngeal carcinoma have been also described presenting perineural spread [7].

Pituitary adenomas account for 15% of all intracranial neoplasms. The majority of pituitary tumours demonstrate a benign phenotype, growing slowly over many years, without local invasion. A smaller subset of these adenomas demonstrate aggressive features, including local invasion of bone or cavernous sinus, and/or rapid enlargement over short intervals. These invasive features tend to correlate poorly with tumour progression [8].

Pituitary apoplexy (PA) was defined as a clinical syndrome in 1950. It is a severe and potentially fatal medical condition characterised by the variable association of headache, vomiting, visual impairment, ophthalmoplegia, altered mental state and panhypopituitarism. The syndrome is often related to haemorrhagic infarction of the pituitary gland, usually in a condition of a pre-existing macroadenoma, occurring in 1.6 to 2.8 % of patients with this neoplasm. In some patients this clinical syndrome represents the first sign of a previously undetected adenoma [9].

MR imaging is the method of choice for evaluation [2, 10] of both perineural invasion and sellar region. The imaging hallmark to demonstrate direct nerve invasion is thickening and complete enhancement of the nerve in T1-weighted sequences [3, 11].

Transsphenoidal surgery was performed and the tumour was partially removed. Pituitary adenoma apoplexy was confirmed by histology.

This case shows typical radiologic and clinical features of a pituitary adenoma apoplexy but perineural extension through trigeminal nerve is an uncommon finding associated to this entity. To our knowledge this features associated to a hypophyseal macroadenoma has not been described neither in the largest radiology series nor as a case report [12].

Cranial nerves should be always examined carefully when facing a tumour in the head and neck area.
MR is the best imaging tool to evaluate a potential perineural growth of a tumour.

Differential Diagnosis List
Pituitary macroadenoma apoplexy with perineural invasion of the left trigeminal nerve
Nasopharyngeal carcinoma
Meningioma
Lymphoma
Metastasis
Pituitary adenoma
Final Diagnosis
Pituitary macroadenoma apoplexy with perineural invasion of the left trigeminal nerve
Case information
URL: https://www.eurorad.org/case/15740
DOI: 10.1594/EURORAD/CASE.15740
ISSN: 1563-4086
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