Acromegaly associated with a granular cell tumor of the neurohypophysis: A clinical and histological study

Marco Losa, Wolfgang Saeger, Pietro Mortini, Claudio Pandolfi, Maria Rosa Terreni, Gianluca Taccagni, Massimo Giovanelli

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Abstract

Acromegaly is usually caused by a growth hormone (GH)-secreting pituitary adenoma, and hypersecretion of GH-releasing hormone (GHRH) from a hypothalamic or neuroendocrine tumor accounts for other cases. The authors report on the unusual association of acromegaly with a granular cell tumor of the neurohypophysis. A 42-year-old woman with a 10-year history of acral enlargement, headache, and menstrual abnormalities was referred to our department for a suspected GH-secreting pituitary adenoma. The patient's basal GH levels were mildly elevated at 4.8 μg/L, were not suppressed in response to an oral glucose tolerance test, and increased paradoxically after administration of thyrotropin-releasing hormone. The patient's insulin-like growth factor-1 (IGF-1) level was elevated at 462 μg/L, whereas a magnetic resonance image of the sella turcica revealed an intra- and suprasellar lesion that was compatible with a diagnosis of pituitary adenoma. A transsphenoidal approach to remove the lesion, which was mainly suprasellar, was successful during a second operative attempt, resulting in the clinical and biochemical regression of the patient's acromegaly. Four months postoperatively, the patient's basal GH level was 0.9 μg/L and her IGF-1 level was 140 μg/L. Histological analysis of the operative specimen demonstrated a granular cell tumor of the neurohypophysis, which when stained proved negative for pituitary hormones and GHRH. This case represents the first reported association between a granular cell tumor of the neurohypophysis and acromegaly. Granular cell tumor of the neurohypophysis could be added to the restricted list of neoplastic causes of acromegaly secondary to hypersecretion of a GH-releasing substance.

Original languageEnglish
Pages (from-to)121-126
Number of pages6
JournalJournal of Neurosurgery
Volume93
Issue number1
Publication statusPublished - Jul 2000

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Keywords

  • Acromegaly
  • Granular cell tumor
  • Growth hormone-releasing hormone
  • Neurohypophysis
  • Pituitary tumor

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Losa, M., Saeger, W., Mortini, P., Pandolfi, C., Terreni, M. R., Taccagni, G., & Giovanelli, M. (2000). Acromegaly associated with a granular cell tumor of the neurohypophysis: A clinical and histological study. Journal of Neurosurgery, 93(1), 121-126.