Contributed by Bonnie Cole, Thomas J. Montine, Lawrence True, Joshua Sonnen
Department of Pathology, University of Washington, Seattle
The patient was a 70-year-old man who was diagnosed 8 years prior to death with prostate adenocarcinoma. He underwent a radical prostatectomy. Pathological examination showed Gleason sum score of 3 + 4 = 7 / 10 with positive surgical margins and extracapsular extension. Serum PSA remained elevated post-op. Despite androgen deprivation therapy, chemotherapy and radiotherapy the tumor progressed, manifesting primarily as bone metastases. He was placed on hospice care 6 months prior to death.
At autopsy he had a pineal gland mass, measuring 1.3 centimeters in diameter and extending into the quadrigeminal cistern (Figure 1). On sectioning, the mass was tan-gray with a rough, granular texture (Figure 2). There was no extension into adjacent brain parenchyma. The mass impinged on the quadrigeminal plate with apparent compression of the cerebral aqueduct (Figure 3). The lateral ventricles and third ventricle were slightly enlarged and the angles of the lateral ventricles appeared blunted.
The remainder of the autopsy demonstrated systemic metastases, involving paraaortic and mediastinal lymph nodes, all lobes of the lungs, and multiple bony metastases including the lumbar spine, pelvis, ribs bilaterally, and upper and lower extremities.
Histologic examination of the pineal mass revealed a neoplasm composed of large epithelioid cells arranged as nests and glands (Figure 4). There was marked necrosis. The neoplastic cells had prominent cell borders and abundant pink cytoplasm with prominent nucleoli. Immunohistochemistry revealed uniform cytoplasmic immunoreactivity for prostate specific antigen (Figure 5). The edges of the tumor were rimmed by pineal parenchyma that showed changes appropriate for age. No other intracranial lesions were found.
The patient also had gross changes that were consistent with acute hydrocephalus. The lateral and third ventricles were slightly enlarged, the angles of the lateral ventricles were blunted, and the cerebral aqueduct was compressed by the adjacent tumor. The patient, however, had no apparent symptoms of obstructive hydrocephalus, though symptoms could have been masked by the patient's limited mobility and high doses of narcotic medications for pain control.