Pilocytic Astrocytoma with subarachnoidal spread

Abstract

Pilocytic Astrocytomas (WHO I) are histopathologically tumors of glial origin occurring predominantly in childhood and adolescence. Normally, they are characterized by a benign clinical course, with a long overall survival time and a high rate of complete remission. The rare case of pilocytic astrocytoma, primarily located in the third ventricular region, with generalized subarachnoidal spread is described. In the 10 years of follow-up, the histopathologic findings of the seedings remained those of a typical pilocytic astrocytoma; tumor progression did not occur.

Spinal Seeding of a Pilocytic Astrocytoma following Multiple Subtotal Resections

“…The incidence of LMD in patients with PAs is indicated to range from 4% up to 12% [1, 8, 16, 22], which would possibly increase with the widespread use of MRI in cases of PAs to report leptomeningeal metastases. Yet, craniospinal metastases were stated synchronously or delayed and were independent of progression of the primary tumor [1, 2, 4,6,7,8,9, 11, 12, 14,22,23,24]. …”

“…PAs mainly originate close to the optic chiasm and hypothalamus, in the cerebellum, in the brainstem, and, less commonly, in the cerebral hemispheres and ventricles [4, 5]. Leptomeningeal dissemination (LMD) without malignant transformation of the primary tumor is rare and several case reports in the literature did or did not present LMD initially [1, 2, 4,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21]. The incidence of LMD in patients with PAs is indicated to range from 4% up to 12% [1, 8, 16, 22], which would possibly increase with the widespread use of MRI in cases of PAs to report leptomeningeal metastases.…”

Pilocytic Astrocytoma in a Cat

“…In human subjects pilocytic astrocytoma occurs mainly in children and young adults. 2,3 Brain tumors in cats present a diagnostic challenge to the veterinary practitioner. Presenting signs can be diverse and usually have an insidious onset.…”

“…With the exception of lymphomas, intracranial neoplasms usually develop in cats older than 9 years of age, which is the age range recorded in this case. In human subjects pilocytic astrocytoma occurs mainly in children and young adults 2,3…”

Spinal Seeding of a Pilocytic Astrocytoma in an Adult, Initially Diagnosed 18 Years Previously

“…Leptomeningeal dissemination (LMD) is a rare phenomenon that can either present at the time of the initial tumor diagnosis, or secondarily, independent of progression of the primary CNS tumor [1,4,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24]. LMD characteristically occurs with the more aggressive, malignant CNS tumors, including high-grade gliomas, medulloblastomas, and germ cell tumors; it has been estimated to occur in only 4–12% of grade I gliomas [4,8,20,21,23].…”