Multidisciplinary Management of Concomitant Spindle Cell Oncocytoma of the Adenohypophysis and Primary Hyperparathyroidism

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 164-196-Pituitary
Basic/Clinical
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-176
Sally Abell*1, Glenn Ward2, Jason Tan2, Penelope McKelvie2, Peter McNeill3 and Carmela Caputo2
1St. Vincent's Hospital, Melbourne, Australia, 2St Vincent's Hospital, Melbourne, Australia, 3St Vincent's Hospital, Melbourne
Background

Spindle Cell Oncocytoma (SCO) of the adenohypophysis are rare tumours characterized by absence of cellular anaplasia, mitoses and necrosis, and low Ki-67 proliferation index. Although benign, the lesions are hypervascular and can recur, with little evidence for sensitivity to radiation.

 Clinical Case

A 55 year old male presented with depressed mood, low libido, lethargy, headache and diplopia. Past history included resection of a giant cell tumour of the humerus and fibroma of the radius. Clinically, he was hypogonadal with bitemporal hemianopia.

 Biochemistry: calcium 2.90mmol/L (2.12-2.63), PTH 232pg/mL (12-65), vitamin D 22nmol/L (75-150), creatinine 103micromol/L (64-104). Hormonal profile: cortisol 288nmol/L, PRL 395mIU/L (73-410), TSH 6.64 mU/mL (0.35-4.94), fT4 13pmol/L (9-19), LH 1.2 IU/L (1.1-8.8), FSH 1.8 IU/L (1.0-12) and Testo <0.7 nmol/L (8-29), IGF-1 <4nmol/L (11-31). Short synacthen test confirmed preserved adrenal function. 

 MRI revealed a giant, homogeneous sellar mass 34x34x58mm projecting into the suprasellar cistern and third ventricle, with local bony erosion, displacement of the cavernous sinuses and compression of the optic chiasm. Parathyroid imaging was concordant for a right lower pole parathyroid lesion.

 Management

Hypercalcaemia was managed with saline and pamidronate achieving nadir calcium of 2.64mmol/l. Transsphenoidal resection removed one third of tumour bulk, limited by its vascular and friable texture. Plans were made for gross total resection (GTR) via 2 further stages. Second surgery achieved 80% tumour clearance.  Post-operatively the patient was commenced on hydrocortisone, thyroxine and testosterone.

 Histology demonstrated interlacing fascicles of spindle cells with eosinophilic granular cytoplasm. There was mild nuclear atypia, no mitoses or necrosis consistent with WHO Grade I SCO. Immunohistochemistry included S100+, TTF-1+, and EMA- with Ki-67 2%. 

 Final debulking surgery was delayed due to symptomatic hypercalcaemia (3.5mmol/L) necessitating parathyroidectomy. Histology confirmed 20x15x6mm parathyroid adenoma. The patient awaits final pituitary surgery to achieve GTR, followed by radiotherapy if remnant tumour exists.

 Conclusion:

This is the 17th reported case of SCO 2. These lesions are hypervascular, necessitating staged operations to achieve GTR. This case was complicated by concomitant primary hyperparathyroidism. The association of benign tumours of the parathyroid and bone is of unknown significance.

1. Spindle cell oncocytoma of the adenohypophysis: a tumor of follicostellate cells? Roncaroli F et al.  Am J Surg Pathol. 2002;26:1048–1055. 2. Spindle cell oncocytoma of the adenohypophysis with marked hypervascularity. Case report. Fujisawa. H et al. Neurol Med Chir (Tokyo). 2012;52(8):594-8.

Nothing to Disclose: SA, GW, JT, PM, PM, CC

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm