Diagnosis and Treatment > Signs and Symptoms
Search for other papers by Sharmin Jahan in
Google Scholar
PubMed
Search for other papers by M A Hasanat in
Google Scholar
PubMed
Search for other papers by Tahseen Mahmood in
Google Scholar
PubMed
Search for other papers by Shahed Morshed in
Google Scholar
PubMed
Search for other papers by Raziul Haq in
Google Scholar
PubMed
Search for other papers by Md Fariduddin in
Google Scholar
PubMed
Summary
Silent corticotroph adenoma (SCA) is an unusual type of nonfunctioning pituitary adenoma (NFA) that is silent both clinically and biochemically and can only be recognized by positive immunostaining for ACTH. Under rare circumstances, it can transform into hormonally active disease presenting with severe Cushing syndrome. It might often produce diagnostic dilemma with difficult management issue if not thoroughly investigated and subtyped accordingly following surgery. Here, we present a 21-year-old male who initially underwent pituitary adenomectomy for presumed NFA with compressive symptoms. However, he developed recurrent and invasive macroadenoma with severe clinical as well as biochemical hypercortisolism during post-surgical follow-up. Repeat pituitary surgery was carried out urgently as there was significant optic chiasmal compression. Immunohistochemical analysis of the tumor tissue obtained on repeat surgery proved it to be an aggressive corticotroph adenoma. Though not cured, he showed marked clinical and biochemical improvement in the immediate postoperative period. Anticipating recurrence from the residual tumor, we referred him for cyber knife radio surgery.
Learning points:
-
Pituitary NFA commonly present with compressive symptoms such as headache and blurred vision.
-
Post-surgical development of Cushing syndrome in such a case could be either drug induced or endogenous.
-
In the presence of recurrent pituitary tumor, ACTH-dependent Cushing syndrome indicates CD.
-
Rarely a SCA presenting initially as NFA can transform into an active corticotroph adenoma.
-
Immunohistochemical marker for ACTH in the resected tumor confirms the diagnosis.
Faculty of Medicine, Westmead Hospital, University of Sydney, Sydney, 2145, Australia
Search for other papers by Kharis Burns in
Google Scholar
PubMed
Department of Endocrinology, Royal North Shore Hospital, St Leonards, 2065, Australia
Search for other papers by Darshika Christie-David in
Google Scholar
PubMed
Faculty of Medicine, Westmead Hospital, University of Sydney, Sydney, 2145, Australia
St Vincent's Clinical School, University of New South Wales, Sydney, 2010, Australia
Diabetes and Transcription Factors Group, Garvan Institute of Medical Research (GIMR), Sydney, 2010, Australia
Department of Diabetes, Obesity and Endocrinology, The Westmead Institute for Medical Research, The University of Sydney, Sydney, 2045, Australia
Search for other papers by Jenny E Gunton in
Google Scholar
PubMed
Summary
Ketoconazole was a first-line agent for suppressing steroidogenesis in Cushing's disease. It now has limited availability. Fluconazole, another azole antifungal, is an alternative, although its in vivo efficacy is unclear. A 61-year-old female presented with weight gain, abdominal striae and worsening depression. HbA1c increased to 76 mmol/mol despite increasing insulin. Investigations confirmed cortisol excess; afternoon serum cortisol was 552 nmol/l with an inappropriate ACTH of 9.3 pmol/l. In total, 24-h urinary free cortisol (UFC):creatinine ratio was 150 nmol/mmol with failure to suppress after 48 h of low-dose dexamethasone. Pituitary MRI revealed a 4-mm microadenoma. Inferior petrosal sinus sampling confirmed Cushing's disease. Transsphenoidal resection was performed and symptoms improved. However, disease recurred 6 months later with elevated 24-h UFC >2200 nmol/day. Metyrapone was commenced at 750 mg tds. Ketoconazole was later added at 400 mg daily, with dose reduction in metyrapone. When ketoconazole became unavailable, fluconazole 200 mg daily was substituted. Urine cortisol:creatinine ratio rose, and the dose was increased to 400 mg daily with normalisation of urine hormone levels. Serum cortisol and urine cortisol:creatinine ratios remain normal on this regimen at 6 months. In conclusion, to our knowledge, this is the first case demonstrating prolonged in vivo efficacy of fluconazole in combination with low-dose metyrapone for the treatment of Cushing's disease. Fluconazole has a more favourable toxicity profile, and we suggest that it is a potential alternative for medical management of Cushing's disease.
Learning points
-
Surgery remains first line for the management of Cushing's disease with pharmacotherapy used where surgery is unsuccessful or there is persistence of cortisol excess.
-
Ketoconazole has previously been used to treat cortisol excess through inhibition of CYP450 enzymes 11-β-hydroxylase and 17-α-hydroxylase, though its availability is limited in many countries.
-
Fluconazole shares similar properties to ketoconazole, although it has less associated toxicity.
-
Fluconazole represents a suitable alternative for the medical management of Cushing's disease and proved an effective addition to metyrapone in the management of this case.