Pituitary carcinoma with different hormone expressions

Abstract

Objective To introduce the experience of diagnosing and treating one case of pituitary carcinoma with distinct hormone expressions in primary and metastatic lesions and to improve understanding of this disease.  Methods Retrospective study was performed to analyze the clinical manifestations, imaging characteristics, histopathologic findings, and treatment information of the patient. Immunohistochemical staining was done to both primary and metastatic lesions.  Results The patient presented with eye pain and discomfort 4 months posterior to pituitary adenoma surgery. Head MRI showed multiple abnormal intracranial signals, irregular pituitary contour, and abnormal enhancements of the sellar region. PET-CT scan showed multiple hypermetabolic lesions. After the first surgery, histological study of the pituitary tumor showed disseminated tumor cells. The cells were round-shaped or polygonal, with mild atypia, moderate amount of eosinophilic plasma and round-shaped nuclei with fine chromatin and unconspicuous nucleoli; mitosis was abundant, while necrosis was absent. The tumor cells expressed P53, chromogranin A (CgA), with scattered expression for growth hormone (GH) and a Ki-67 index of 80% by immunohistochemistry. The first pathologic diagnosis was atypical pituitary adenoma. The parietal tumor cells infiltrated parenchymal after the tumor recurrence. Immunohistochemistry findings were different from the first one. The tumor cells expressed GH diffusely, with a decreased Ki-67 index of 75%. The second pathologic diagnosis was metastatic pituitary carcinoma.  Conclusions Pituitary carcinoma is a rare malignant pituitary tumor. Diagnosis relies on radiology and pathology. Surgical resection and radiochemotherapy are the current treatment of choice but yield poor response. General prognosis of the disease is poor.

DOI: 10.3969/j.issn.1672-6731.2015.01.013