Endocrine Abstracts

We present the case of a 19 year old female who presented to A&E with a three week history of nausea, vomiting and constipation. She was noted to have hypercalcaemia at 4.11 mmol/l. There was no family history of note and prior to this illness she had been fit and well with no regular medications. Investigations revealed a suppressed PTH of <0.6 pmol/L. U&E, vitamin D, TSH, serum ACE and cortisol were within normal range.

Examination revealed a suprapubic mass thought to be a distended bladder. Further investigation with USS and CT scans abdomen and pelvis revealed a 17 cm left ovarian mass. Her CA125 was markedly raised at 320 ku/l. She was transferred to the care of the gynaecology team who performed a laparotomy and left salpingo-opherectomy. Histology confirmed an ovarian small cell carcinoma of hypercalcaemic type (OSCCHT), FIGO stage 2b, later on PET scanning found to be stage 3b-4. Genetics confirmed a SMARCA4 gene inactivating mutation.

This case represents a rare presentation of hypercalcaemia in a young woman. Hypercalcaemia is an uncommon occurrence in gynaecological malignancies, occurring in around 5% of ovarian cancers. It is more common within the rarer ovarian cancer subtypes and indeed present in 66% of OSCCHT cases. This rare and aggressive tumour type affects young females, and in half of cases has extra-ovarian spread at diagnosis. First described in 1982, it has until recently has evaded cytogenetic or molecular classification. In 2014 the pathology ‘enigma’ was decoded by Foulkes et al. who identified deletion mutations in the chromatin-remodelling gene SMARCA4 (encoding BRG1). This gene has been linked to various other human cancer types (including breast, prostate, lung, pancreas and colon) and is mutated in most rhabdoid tumours.