Pituitary Abscess With Unusual Clinical Course

Abstract

SUMMARY -Th e aim is to present unusual clinical course and magnetic resonance imaging (MRI) features of pituitary abscess. A 59-year-old man presented with fever, polyuria, polydipsia and marked weight loss within the last two months. Basic endocrinology tests revealed the presence of anterior pituitary dysfunction, associated with central diabetes insipidus and increased levels of infl ammatory markers. Th e presence of expansile sellar lesion, showing restricted diff usion signal pattern compatible with acute pituitary pyogenic abscess was found on MRI. Regression of pituitary abscess was obvious during the next few weeks of parenteral antibiotic treatment. Adequate substitution treatment with L thyroxine, hydrocortisone, testosterone and desmopressin was achieved. Seventeen months later, clinical deterioration associated with recurrent pituitary abscess was confi rmed on MRI. Abscess regression was obvious again after conservative treatment. However, control MRI study performed three years after initial scanning revealed the presence of pituitary tumor, most consistent with macroadenoma. Surgical intervention was ordered. Histologic evaluation indicated the presence of fi brotic changes, associated with granulation tissue and rare cellular elements, compatible with chronic infl ammation. To the best of our knowledge, there are no studies in the literature describing such a pattern of chronic evolution of pyogenic pituitary abscess with consequent chronic infl ammatory changes with granulation tissue proliferation, mimicking macroadenoma.

Atypical pituitary abscess lacking rim enhancement and diffusion restriction with an unusual organism, Moraxella catarrhalis: A case report and review of the literature

“…DWI is useful for the differential diagnosis of PA, other sellar cystic lesions,[ 1 , 9 , 12 , 16 , 18 - 21 ] as well as cerebral abscesses. [ 25 ] So far, the evaluation of PA on DWI has been reported in 12 cases, summarized in [ Table 1 ].…”

“…[ 25 ] Thus, evaluation with both gadolinium-enhanced T1-weighted imaging and DWI is useful to distinguish PA from other sellar cystic lesions. [ 1 , 9 , 12 , 16 , 18 - 21 ] Herein, we report an atypical case of PA, suffered from Moraxella catarrhalis , showing neither rim enhancement nor diffusion restriction. In general, M. catarrhalis causes otitis media and sinusitis in children, and bronchitis and pneumonia in the elderly.…”

Nocardial Brain Abscess Mimicking Lung Cancer Metastasis in Immunocompetent Patient with Pulmonary Nocardiasis: A Case Report

“…in some situations, it is very difficult to draw clear distinction between brain abscesses and other multiple brain lesions such as secondary deposits. Additional tools and sequences such as magnetic resonance proton spectroscopy (mRs) or diffusion weighted imaging (dwi) delineating biochemical changes and structural changes at the cellular level in target lesion can be helpful not only in diagnosis but also in following-up the effects of therapy applied [10][11][12] .…”

Nocardia Brain Abscess Mimicking Metastases in an Immunocompromised Patient

“…Still, a distinction between a brain abscess and another brain lesion can be difficult with MRI alone. Magnetic resonance proton spectroscopy (MRS) and diffusion-weighted imaging (DWI) are sometimes employed to better differentiate the lesion [18][19][20]. However, subsequent work-up with pathologic examination, in addition to imaging and clinical findings, is required for definitive diagnosis.…”