CLINICAL QUESTION How should a nonfunctioning pituitary macroadenoma be monitored after debulking surgery? Yona Greenman and Naftali Stern Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center and the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Summary Transsphenoidal surgery is the treatment of choice for nonfunc- tioning pituitary macroadenomas but is seldom curative. Tumour progression rates are high in patients with postoperative remnants. Therefore, long-term monitoring is necessary to detect tumour growth, which may be asymptomatic or manifest with visual field defects and/or pituitary dysfunction. In view of the generally slow- growing nature of these tumours, yearly magnetic resonance imag- ing, neuro-ophalmologic and pituitary function evaluation are appropriate during the first 3–5 years after surgery. If there is no evidence for tumour progression during this period, testing inter- vals may be extended thereafter. (Received 6 January 2009; returned for revision 19 January 2009; finally revised 21 January 2009; accepted 21 January 2009) Most clinically nonfunctioning pituitary adenomas (NFPA) are of gonadotroph cell origin, but rarely manifest with clinical signs or symptoms related to gonadotropin excess. Headaches, visual field compromise and decrease in visual acuity, as well as hypopituita- rism are the most common presenting features of NFPA, and are all induced by pressure of the tumour on surrounding structures. Therefore, tissue decompression is the main therapeutic goal in NFPA, being effectively achieved in most cases through transsphe- noidal excision of the tumour. Nevertheless, these usually large and invasive tumours often cannot be completely resected. NFPA patients need long-term surveillance, although the best means and frequency of follow-up have not been clearly established. The mon- itoring strategy used in our institution and presented herein has evolved based on published observational studies on the natural history of NFPA, and clinical experience. The problem of lack of secretory markers In clinically functioning pituitary adenomas, circulating hormone levels are accurate tumour markers. Hence, the presence of elevated serum hormone concentration may indicate incomplete surgical resection or tumour recurrence even in face of an apparently nor- mal imaging study. This important tool is lacking for the follow-up of most NFPA, as elevated gonadotropins are detected only in a minority of patients on basal conditions, and the TRH-induced increase in b-subunits is not a sufficiently reliable marker for the presence of residual tumour. 1 Consequently, detection of recur- rence or residual tumour growth relies directly on imaging studies, or is indirectly based on appearance of new defects or deterioration of previously impaired visual and pituitary function. Early postoperative assessment Visual fields Resolution of headaches and amelioration of visual field defects occur shortly after surgery in the majority of patients. The recovery of visual fields is progressive, with an early fast phase of improve- ment during the first week after surgery, an early slow phase (4–6 months postoperatively) by the end of which most of the eventual recovery takes place and a late phase (up to 3–5 years) in which mild further improvement may still occur. 2 Overall, normal- ization of visual function occurs in 35–39% and improvement in 50–60% of patients. 2,3 Worsening of vision is reported in 0Æ5–2Æ4% of patients, and as with other surgical complications, its prevalence depends on the experience of the neurosurgeon and the volume of operations performed in a particular centre. 4 Based on these data, a neuroophthalmological assessment should be performed 1 week and again after 3–6 months following surgery. The visual status obtained in these evaluations will be the baseline for subsequent comparisons. Pituitary function In most 5 but not all 6 series, normalization of one or more hypo- thalamo-pituitary–axis function has been reported after surgery, whereas worsening of pituitary function is less common. The degree of improvement is variable, occurring in 15–50% of Correspondence: Yona Greenman, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center, 6 Weizmann Street, Tel Aviv 64239, Israel. Tel: +972 36973899; Fax: +972 36973053; E-mail: greenman@tasmc.heatlh.gov.il Clinical Endocrinology (2009) 70, 829–832 doi: 10.1111/j.1365-2265.2009.03542.x Ó 2009 Blackwell Publishing Ltd 829