acromegaly is a disorder resulting from uncontrolled hypersecretion of growth hormone ( gh ) and associated gh - mediated production of insulin - like growth factor 1 ( igf-1 ) from the liver . most of these tumors are large and nearly always visible on magnetic resonance imaging ( mri ) of the sellar region . acromegaly secondary to a very small pituitary microadenoma not visualized on pituitary mri is rare . there had been only three previous reports of acromegalic patients with negative pituitary imaging , in whom subsequently adenomas could be identified on pituitary exploration . a 32-year - old gentleman was admitted to us with chief complaints of acral enlargement , headache and poorly controlled diabetes for last 3 years , and recently diagnosed hypertension . on examination , he had frontal bony prominence , widening of teeth spaces in lower jaw , macroglossia , and acral enlargement . his blood pressure was 140/88 mmhg on amlodepine 10 mg / day and losartan 100 mg / day . his fasting blood sugar was 160 mg / dl and glycated hemoglobin was 8.5% on glimepiride 6 mg / day and metformin 2 g / day . he was shifted to insulin and required total of 38 units insulin daily for glycemic control . with the provisional diagnosis of acromegaly further investigations were planned . elevated serum igf-1 levels , with unsuppressed serum gh levels ( nadir serum gh level of 11.3 ng / ml ) during oral glucose suppression test with 100 gram of glucose ( both serum gh and igf-1 were measured on an autoanalyzer , roche elecsys 2010 , using electrchemiluminometric assay ) , confirmed the diagnosis of acromegaly . contrast - enhanced mri sella with dynamic images was done , which showed a small nonenhancing area near to the floor of sella [ figures 1 and 2 ] ; however , the appearance on dynamic scans was not typical for a microadenoma and hence limited computed tomography ( ct ) of sellar region was done which showed this lesion to be bony and arising from the floor of sella [ figure 3 ] and appeared as sellar floor osteoma . subsequently , mri with special volumetric interpolated breath - hold examination ( vibe ) sequences was done , which also failed to show any pituitary adenoma . subsequently , for ectopic source of gh secretion localization , contrast - enhanced ct scan of chest , abdomen and pelvis was done , which was normal . thereafter , a decision was taken to explore the pituitary , and he underwent transnasal transsphenoidal exploration of pituitary , and a pituitary adenoma infiltrating dura could be identified and removed . histopathologic examination of the resected lesion confirmed it as gh positive pituitary adenoma . hormonal analysis of patient t1-weighted sagittal mri image ( a ) shows a small hypointense area in the anterior pituitary which has the same appearance on post - contrast image ( b ) t1-weighted coronal mr image ( a ) pre - contrast and ( b ) post - contrast shows the same lesion with no enhancement ct sella of the same patient , sagittal reformatted image ( a ) and coronal reformatted image ( b ) showing the lesion to be bony and arising from the floor of sella acromegaly is a disorder resulting from uncontrolled hypersecretion of gh and associated gh - mediated production of igf-1 from the liver . the elevated gh and igf - i levels in acromegaly lead to a wide range of cardiovascular , respiratory , endocrine , and metabolic morbidities . the clinical manifestations range from subtle signs of acral overgrowth , soft - tissue swelling , arthralgias , jaw prognathism , fasting hyperglycemia , and hyperhidrosis to florid osteoarthritis , frontal bone bossing , diabetes mellitus , hypertension , and respiratory and cardiac failure . however , untreated acromegaly is associated with a significant morbidity and a reduced life expectancy . so , once biochemical diagnosis of acromegaly is confirmed , pituitary mri is the first step in localizing the gh excess . adenomas precipitating acromegaly are usually more than 1 cm in diameter at the time of diagnosis and nearly always visible on conventional mri . other rare causes of acromegaly include pituitary somatotroph carcinomas , hypothalamic tumors secreting growth - hormone - releasing hormone ( ghrh ) , and a nonendocrine tumors causing ectopic secretion of gh or ghrh . so , if pituitary mri is unremarkable , contrast - enhanced ct scan of chest , abdomen and pelvis is the next step to look for ectopic source of gh / ghrh . acromegaly secondary to a very small pituitary microadenoma not visualized on pituitary mri is rare . to the best of our knowledge , previously there had been only three reports of acromegalic patients with negative pituitary imaging , in whom subsequently adenomas could be identified on pituitary exploration . described three acromegalic patients in whom mri imaging failed to detect a pituitary adenoma that was later discovered at surgery ( resected adenoma sizes : 6 , 7 , and 10 mm , respectively ) . the other two patients had only noncontrast mri imaging , which may not be a sensitive imaging for small adenomas . reported an acromegalic patient who did not have imaging evidence of a pituitary adenoma with contrast - enhanced mri , including thin - cut spoiled - gradient recalled ( spgr ) imaging . lonser et al . recently reported a series of six acromegalic patients without imaging evidence of pituitary adenoma on conventional contrast - enhanced mri , who also lack an ectopic source . subsequently , postcontrast fine - cut vibe mri sequence revealed a 4-mm pituitary adenoma in one out of three patients , who had this special mri sequence imaging . however , on surgical exploration , pituitary microadenomas could be identified in all cases . in our case , imaging with conventional mri ( 1.5 t magnet ) , followed by a second , fine - cut vibe sequence , failed to reveal a pituitary adenoma . however , on surgical exploration , a pituitary adenoma infiltrating dura could be identified and removed . to rule out an ectopic source of gh / ghrh , we had done contrast - enhanced ct scan of chest , abdomen and pelvis , as well as nuclear imaging ga - dotanoc , both of which did not show any ectopic source . currently , there is no consensus for the treatment of patients with acromegaly and negative pituitary imaging . medical therapy is one of the other treatment options in these patients ; however , our patient was not able to afford long - term medical treatment and opted for surgical exploration after discussion . previously , there had been few case reports of osteoma in association with acromegaly and in one of the cases , even progression of osteoma related to acromegaly .