[Acute Changes in the Computed Tomography Findings of Mucocele Combined with Pituitary Adenoma:A Case Report].

INTRODUCTION: We report a rare case in which a pituitary tumor co-occurred with a giant mucocele. The mucocele's computed tomography(CT)values fell markedly when it collapsed, and we report the associated considerations.

CASE: This case involved a 42-year-old male patient. For 20 years, his visual acuity had progressively declined, and it suddenly rapidly worsened over a month. Cranial CT revealed a massive tumor in the sphenoid sinus and a pituitary tumor. A region of high absorption extended from the paranasal sinus to the skull base. Two days after the patient's initial presentation, he experienced a sudden loss of vision. Therefore, we performed an urgent re-examination. The CT value of the paranasal lesion was found to have sharply declined. The sinus lesion was diagnosed as a mucocele. Emergent endoscopic surgery was performed. <i>Actinomyces meyeri</i> was detected in the samples cultures.

DISCUSSION: The causes of mucocele exhibiting abnormally high signal intensity on CT include the accumulation of hemosiderin due to repeated bleeding in the cyst. Furthermore, we inferred that the <i>Actinomyces meyeri</i> had been taking up metallic elements in vivo for a long time. The marked reduction in the lesion's CT value was considered to have been due to the destruction of the mucocele. The contents of the mucocele flowed out and were replaced with newly produced mucus, which exhibits low absorption values.

CONCLUSION: We treated a patient with a giant mucocele involving distraction of the frontal base and a pituitary adenoma. In such cases, surgery should be performed when visual acuity deteriorates suddenly.