Hypopituitarism associated with mycotic aneurysm of the cavernous carotid artery in a renal transplant recipient

Abstract

Keywords: diabetes insipidus; hypopituitarism;internal carotid artery; mycotic aneurysm;renal transplantHypopituitarism is a rare complication of aneurysmsprojecting into the sellar region or cavernoussinus thrombophlebitis [1]. Infective intracavernousaneurysms are rarely described in renal transplantrecipients [2]. We report a case of hypopituitarismassociated with mycotic aneurysm of the internalcarotid artery (ICA) in a renal transplant recipientafter successful treatment of a post-transplant lympho-proliferative disorder.A 23-year-old man presented with horizontal diplo-pia. He had received a cadaveric renal transplant2 years before. Six months after transplantation, hewas diagnosed with post-transplant lymphoprolifera-tive disorder located in the nasopharynx. Completeremission was achieved after withdrawal of immuno-suppression and treatment with immunochemotherapyand radiotherapy. Low-dose corticosteroids wereinitiated to prevent graft rejection. One year later, thepatient was admitted with visual disturbances andhorizontal diplopia. A cranial CT scan revealed grossmucosal thickening in the right maxilar and sphenoidalsinuses. Two days later, he developed pain in theright eye, proptosis and chemosis along with epistaxis.A cavum biopsy ruled out lymphoma relapse. Thefollowing day, he developed right III, IV, V and VInerve palsy along with left hemiparesia and fever.Empirical therapy with meropenem and voriconazolewas initiated. Propionibacterium spp. was isolated fromblood cultures and long-term antibiotherapy wasmaintained. Magnetic resonance (MR) angiographyshowed narrowing of the sphenoidal sinus, an aneu-rysm of the intracavernous portion of the right ICAwith extension into the pituitary fossa and an areaconsistent with ischaemic infarction. Twenty-fourhours later, an angiography revealed a pseudoaneu-rysm in the C5 portion of the right ICA siphon(Figure 1A) and balloon occlusion was performed(Figure 1B). After the procedure, his neurologicalsymptoms improved. Hypotonic polyuria was docu-mented and l-desamino-8-arginine-vasopressin wasintravenously administered. Basal endocrine studiesrevealed anterior pituitary failure and undetectablelevels of prolactin. The patient was discharged on pred-nisone, l-thyroxine, testosterone and desmopressin.One year later, MR imaging confirmed radiologicallycure of the aneurysm (Figure 2). Two weeks aftertestosterone and desmopressin withdrawal, endocrinetests were indicative of persistent anterior hypopituita-rism but posterior pituitary function was normal.Although the majority of mycotic aneurysmsare secondary to bacterial endocarditis, sinusitisand cavernous sinus infection are known to causeICA aneurysm. In our case, sinusitis caused byPropionibacterium spp. might have led to the develop-ment of a cavernous sinus thrombofletitis and, subse-quently, the mycotic aneurism. To our knowledge,only one case of ICA mycotic aneurysms has beenpreviously reported in a renal transplant recipient [2],although this case occurred during the acute phase oftransplantation.Nowadays, endovascular techniques are the pre-ferred method of treatment of life-threatening largemycotic aneurysms [2–3]. ICA occlusion after endo-vascular intervention might have precipitated thedevelopment of hypopituitarism in our case, whichis of special interest because the long-term follow-up.The prolactin deficit seen in our patient suggestsdestruction of pituitary tissue that can be due either