Xanthomatous hypophysitis associated with autoimmune disease in an elderly patient: A rare case report

Abstract

Background: Xanthomatous hypophysitis (XH) is an extremely rare form of primary hypophysitis characterized by infiltration of the pituitary gland by mixed types of inflammatory cells, including foamy cells, plasma cells, and small mature lymphocytes. XH manifests as varying degrees of hypopituitarism. Although several previous reports have denied a possible contribution of autoimmune mechanism, the exact pathogenesis of XH remains unclear.

Case description: We describe the case of a 72-year-old woman with a history of rheumatoid arthritis and Sjögren's syndrome who presented with panhypopituitarism and diabetes insipidus. At the time of her visit, she also experienced relapsed rheumatoid arthritis and Sjögren's syndrome, manifesting as arthralgia. Magnetic resonance imaging (MRI) showed a multicystic mass in the sellar and suprasellar regions. In the course of steroid replacement therapy for hypocortisolism, the patient's arthralgia diminished, and MRI revealed shrinkage of the mass. XH was diagnosed histologically following a transsphenoidal endoscopic biopsy, and it was the oldest case of XH.

Conclusion: To the best of our knowledge, this patient is the oldest of reported patients diagnosed with XH. Steroid therapy may be effective to XH temporarily. XH should be considered when diagnosing pituitary cystic lesions in elderly patients with autoimmune disease.

Keywords: Autoimmune disease; hypopituitarism; xanthomatous hypophysitis.

Figure 1

Magnetic resonance imaging from onset to surgery. Sagittal section of T1-weighted images on admission showed thickened pituitary and stalk extending toward the hypothalamus and no evidence of posterior lobe hyperintensity (a). Sagittal and coronal section of gadolinium-enhanced T1-weighted image (b and e) and coronal section of T2-weighted image (c) at the time of her visit showed the intrasellar and suprasellar multicystic lesion with heterogeneous contrast. Coronal section of gadolinium-enhanced T1-weighted image showed the lesion shrinking (f) after transient expanding on admission (e) compared to 1 month ago (d)

Figure 2

Intraoperative picture of the transsphenoidal and tuberculum sellae endoscopic surgery. Intraoperative findings revealed a soft yellowish cystic lesion (➔) along the pituitary stalk (▲) and the optic chiasma (Δ)

Figure 3

Pathological findings of the lesion. The cystic lesion was histologically characterized by infiltration of the anterior pituitary by foamy histiocytes, plasma cells, and lymphocytes (a, ×200). The foamy cells were immunopositive for the macrophage marker CD68 (b, ×200) and immunonegative for CD1a (c, ×200) and S-100 protein (d, ×200). The majority of lymphocytes are immunopositive for CD3 (e, ×200). There was no evidence of pituitary adenoma or granuloma or necrosis

Figure 4

Magnetic resonance imaging after surgery. The postoperative series of magnetic resonance imaging 1 year after the surgery showed no progression of the lesion