Polyuria, Sinopulmonary Symptoms, and Pituitary Mass

•Granulomatosis with polyangiitis (GPA) is a necrotizing granulomatous vasculitis which can affect any organ system, but classically presents with sinopulmonary and renal manifestations.•Pituitary gland involvement is rare, accounting for just 1% of GPA cases.•Among GPA presentations manifesting as endocrinological abnormalities involving the pituitary gland, central diabetes insipidus is the most frequent. A 38-year-old woman presented with a five-week history of polyuria, headaches, intermittent fever, and sinopulmonary symptoms. In the emergency department, CT chest (Fig. 1) demonstrated dense bilateral upper lobe consolidation and CT head (Fig. 2) noted pansinus disease. A water deprivation test was performed and was notable for a urine osmolality of 95 mOsm/kg, serum osmolality of 310 mOsm/kg and serum sodium of 151 mmol/L. Intravenous desmopressin 4 mcg was administered, and subsequent urine osmolality increased to 211 mOsm/kg, consistent with central diabetes insipidus. MRI sella (Fig. 3) demonstrated a 1.2 x 1.6 x 0.8 cm pituitary lesion with central necrosis. Further lab evaluation showed elevated C-reactive protein of 4.2 mg/dL, c-ANCA 1:40 and anti-proteinase-3 antibodies > 8.0 IU/mL positivity. A core biopsy of the right upper lung lobe was performed and demonstrated necrotizing granulomatous inflammation. What is the diagnosis?Figure 2Opacification of paranasal sinuses.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3T1-weighted pituitary mass with central necrosis.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The unifying diagnosis is granulomatosis with polyangiitis (GPA) with an infiltrative pituitary process, resulting in central diabetes insipidus (CDI). GPA, a necrotizing granulomatous vasculitis, can affect any organ system, classically with sinopulmonary and renal manifestations.1Greco A. Marinelli C. Fusconi M. Macri G.F. Gallo A. De Virgilio A. Zambetti G. de Vincentiis M. Clinic manifestations in granulomatosis with polyangiitis.International Journal of Immunopathology and Pharmacology. 2015; 29: 151-159https://doi.org/10.1177/0394632015617063Crossref Scopus (116) Google Scholar Conversely, pituitary gland involvement is rare accounting for 1% of GPA cases.2Guzman-Soto M.I. Kimura Y. Romero-Sanchez G. Cienfuegos-Alvear J.A. Candanedo-Gonzalez F. Kimura-Sandoval Y. Sanchez-Nava D.A. Alonso-Ramon I. Hinojosa-Azaola A. From head to toe: Granulomatosis with polyangiitis.RadioGraphics. 2021; 41: 1973-1991https://doi.org/10.1148/rg.2021210132Crossref PubMed Scopus (12) Google Scholar CDI is the most frequent pituitary hormone abnormality.2Guzman-Soto M.I. Kimura Y. Romero-Sanchez G. Cienfuegos-Alvear J.A. Candanedo-Gonzalez F. Kimura-Sandoval Y. Sanchez-Nava D.A. Alonso-Ramon I. Hinojosa-Azaola A. From head to toe: Granulomatosis with polyangiitis.RadioGraphics. 2021; 41: 1973-1991https://doi.org/10.1148/rg.2021210132Crossref PubMed Scopus (12) Google Scholar MRI sella imaging can demonstrate pituitary enlargement with increased enhancement and infundibulum thickening.2Guzman-Soto M.I. Kimura Y. Romero-Sanchez G. Cienfuegos-Alvear J.A. Candanedo-Gonzalez F. Kimura-Sandoval Y. Sanchez-Nava D.A. Alonso-Ramon I. Hinojosa-Azaola A. From head to toe: Granulomatosis with polyangiitis.RadioGraphics. 2021; 41: 1973-1991https://doi.org/10.1148/rg.2021210132Crossref PubMed Scopus (12) Google Scholar Loss of characteristic hyperintense signal in the posterior pituitary on T1-weighted sequences is strongly correlated with CDI.3Pakalniskis M.G. Berg A.D. Policeni B.A. Gentry L.R. Sato Y. Moritani T. Smoker W.R. The many faces of granulomatosis with polyangiitis: A review of the head and neck imaging manifestations.American Journal of Roentgenology. 2015; 205https://doi.org/10.2214/ajr.14.13864Crossref Google Scholar The importance of early recognition and treatment of such heterogenous presentations may reduce morbidity in sparing patients unnecessary imaging, invasive procedures and prevent irreversible pituitary function loss.