Pseudo-isolated FSH deficiency caused by an inhibin B-secreting granulosa cell tumour: Case report

Abstract

Isolated FSH deficiency due to a mutation in the FSHbeta subunit is characterized by an extremely low serum FSH concentration. We report a patient who presented with an FSH of 0.8 mIU/ml and infertility associated with anovulation. Endocrinological assessment and immunohistochemistry revealed that a granulosa cell tumour was secreting inhibin B and suppressing FSH; however, LH and estradiol were within their normal ranges. Upon removal of the tumour, inhibin B decreased and FSH levels rose to normal values. The patient subsequently conceived and delivered successfully. Based on this case and on those previously described in the literature, we suggest that inhibin B levels should be evaluated in anovulatory patients having a clinical presentation consistent with functional hypothalamic amenorrhoea and very low to normal values of FSH.

Secondary amenorrhoea associated with an isolated elevated serum leuteinising hormone: An unusual presentation of a granulosa cell tumour

“…However, in contrast with our report, presentation was associated with low FSH and normal LH levels (Kurihara et al 2004;Krishnan et al 2003;Sakamoto et al 1998). However, in contrast with our report, presentation was associated with low FSH and normal LH levels (Kurihara et al 2004;Krishnan et al 2003;Sakamoto et al 1998).…”

Inhibin‐producing ovarian granulosa cell tumor as a cause of secondary amenorrhea: Case report and review of the literature

“…Krishnan et al . pointed out that the hormonal findings of an inhibin‐secreting granulosa cell tumor are similar to those of isolated FSH deficiency 10 . Isolated FSH deficiency is a rare cause of idiopathic hypogonadotropic hypogonadism characterized by primary amenorrhea: an absent to low levels of FSH, low levels of estradiol and normal LH.…”

“…There have been several case reports of granulosa cell tumors where the patients presented with secondary amenorrhea 2,5–10 . A summary of these reports is presented in Table 3, and includes a case with fibrothecoma 9 .…”

“…These reports suggested that secondary amenorrhea in women with granulosa cell tumors may primarily be caused by excess inhibin secretion. However, some of the patients with granulosa cell tumors who presented with secondary amenorrhea had normal FSH levels 2,10 . The definitive causes of amenorrhea in these patients were not mentioned, but it was reported that one of them successfully conceived after removal of the tumor 2 …”

Dominance and gene dosage balance in health and disease: why levels matter!

“…A perturbation of the ratio between inhibins and activins can be harmful. For instance, a granulosa cell tumour secreting inhibin B can lead to FSH deficiency and infertility associated with anovulation [51]. This type of interlocus interaction leading to dominance can be considered as a transdominant negative effect (a full account on this subject can be found in [52]).…”