1 Introduction
Pituitary adenomas (PA) are deemed to be rare in old patients; however, with increasing in life expectancy and improvement in health care more pituitary tumours will be diagnosed in old patients. Little is known about PA in the elderly, what are the most frequently presenting symptoms, what are their phenotypes and what are their repercussions. Furthermore, physiological changes and comorbidities of old patients can delay the diagnosis and may significantly influence clinical presentation and outcome of these tumours. The aim of our study is to analyze the features of giant and invasive adenomas in patients aged 60 years and over.

2 Subjects and Methods
This is a retro- and prospective study concerning 37 patients (19F/18M) aged 60 years and over harbouring a pituitary adenoma, these patients were divided into two groups: Group 1 (G1) are patients with giant and/or invasive tumours which means tumours ≥ 40 mm (Figure 1) or tumours invading the cavernous sinuses (Figure 2).

Figure 1 Giant adenoma

Figure 2 Giant adenoma invading cavernous sinuses

 
Group 2 (G2) are patients with tumours < 40 mm without cavernous sinuses involvement. Presenting symptoms were reviewed; all patients underwent a thorough clinical examination, hormonal, radiological and visual assessment.

3 Results
Among 37 adenomas, 38 % (N=14, 9F/5M) were giants and/or invasive. Adenoma size was 40.53 ± 11.38 mm in G1 and 22.7 ± 7.96 mm in G2. Cavernous sinuses were involved in 16 %. Patients of G1 were older than those of G2: 70.71 ± 6.70 years vs 66.17 ± 5.41 years. Neuro-ophtalmological complaints were the most frequent appealing symptoms, present in 78% in G1 and 61% in G2, appealing symptoms are described in Table 1. The adenomas were most often non functioning in both groups: 64% in G1 and 61% in G2, the nature of pituitary adenoma is reported in Table 2. Hormonal assessment revealed pituitary deficiency in 61% in G1 and 60% in G2 whereas visual evaluation found visual impairment in 71% in G1 and 33% in G2.

Table 1 Appealing symptoms

Table 2 Nature of pituitary adenoma

 
4 Discussion
Pituitary adenomas in the elderly are deemed to be rare representing less than 10% of all PA (Barzaghi et al., 2007), although autopsies studies didn’t find differences in the prevalence of PA between old and young patients suggesting that many adenomas are undiagnosed in old subjects (Burrows et al., 1981). However, incidence of PA is increasing due to the increase in life expectancy in one side, on the other side and because old people are prone to neurovascular and neurocognitive diseases, more neuroimaging procedures are performed so many pituitary tumours are incidentally discovered. In our study, in contrast to autopsy series where micro adenomas and prolactinomas are predominating, we found a preponderance of macro adenomas and non functioning adenomas as reported by other authors (Burrows et al., 1997; Cohen et al., 1989; Hong et al., 2008), Hong and al in their report of 103 adenomas, all were macro adenomas and 75% were non functioning (Hong et al., 2008). 38% of our adenomas were aggressive tumours either giants ones or adenomas invading cavernous sinuses, age related changes and associated diseases may explain the delay in diagnosis and the invasiveness of PA as visual abnormalities and clinical manifestations of hypopituitarism are often attributed to ageing. In our study GH secreting adenomas were smaller and less invasive than other types, they were diagnosed only in G2, an age related decrease in cell proliferation rate has been observed in GH secreting adenomas in old patients (Jaffrain-Rea et al., 2002). Conversely, prolactinomas as we observed present clinically as non secreting and are usually invasive (Minniti et al., 2005).

Pituitary tumours are increasingly recognized on cerebral imaging performed for other complaints (Turner et al., 1999) especially in the less invasive tumours as we observed, PA were incidentally discovered only in G2, though these incidentalomas are not really asymptomatic as some of these patients have longstanding symptoms compatible with pituitary tumours that have been misattributed to ageing. Pituitary adenomas in the elderly have frequent and severe repercussions on vision and pituitary function as reported by others (Burrows et al., 1997; Turner et al., 1999) notably in invasive lesions as we observed.

5 Conclusion
Due to age related changes and comorbidities, pituitary adenomas are usually diagnosed late in the elderly at an advanced stage of visual loss and pituitary damage. With improvements of life expectancy these lesions will become more common, so we shall make close attention to patient’s complaints and not systematically attribute these complaints to ageing in order to make an earlier diagnosis and improve patient’s outcome.

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