Hypophysitis secondary to a ruptured Rathke cleft cyst.

CASE REPORT Case 1 A 31-year-old female consulted for polydipsia and polyuria ongoing since a few weeks. She reported weight gain over the last eight months and amenorhea with galactorhea for the last four months. Physical examination revealed no abnormalities other than a decreased visual acuity in the left eye already noticed by the patient over the past three months. Biochemical and hematological data were within normal range. Endocrine work-up showed slightly increased prolactine, decreased luteinizing hormone/follicle stimulating hormone (LH/FHS), decreased free T4 and compensated insipidus diabetes. Magnetic resonance imaging (MRI) demonstrated a sellar cystic lesion with suprasellar extension, displacing the optic chiasm upwardly. The lesion was iso-intense on T1WI and slightly hyperintense on T2WI (Figure 1). The lesion’s rim enhanced following gadolinium injection. The stalk did not enhance. The preoperative diagnosis was a non-secreting cystic macroadenoma. The lesion was approached by an endoscopic endonasal transsphenoidal route. After opening a thin capsule beneath the dura, a whitish viscous substance spontaneously leaked out of the sella (Figure 2). After the mucoid substance was completely aspirated, the angled endoscope enabled a view inside the cavity and removal of free floating fragments of the capsule, sparing the pituitary gland. Intra-operative pathological findings were suggestive of an inflammatory process. In light of this information, the cavity was irrigated and surgery terminated. Post-operatively, the patient fully recovered her visual field defect. Currently two years following surgery, the patient remains on replacement treatment. Her follow-up MRI showed no lesion recurrence. The definitive pathological assessment showed fragments of pituitary tissue, with residual acini among tissue infiltrated with T and B lymphocytes and plasmocytes. A few giant cells were identified in the specimen. One of the fragments was lined by squamous cells, suggestive of a ruptured RCC with secondary hypophysitis (Figure 3). Special stains for micro-organisms yielded negative findings. Hypophysitis Secondary to a Ruptured Rathke Cleft Cyst