PMC9869186_01
A rare presentation of metastatic myxopapillary ependymoma. Magnetic Resonance Imaging (a and b) demonstrating a rare pelvic presentation of metastatic myxopapillary ependymoma. First presentation of pelvic disease is demonstrated in (a) Pelvic MRI (b) demonstrates disease progression after a 24-month period of disease stabilization with adjuvant radiotherapy, prior to final resection. There is evident a complex lobulated mass centered at the level of the coccyx and extending inferiorly and predominantly to the right of the midline, invading the posterior rectal wall and threatening the sciatic nerve, craniocaudal extent 8.9 cm. Status of pelvic disease, recurrent after multiple resections, at the time of presentation with metastatic disease to the thorax is shown in (c) Computed Tomography (d) demonstrating rare presentation of thoracic disease in metastatic myxopapillary ependymoma. Disease is shown at commencement of olaparib-temozolomide, where there is evident extensive intrathoracic involvement (intrapulmonary and pleural), in addition to small-volume pelvic (inguinal) nodal and hepatic disease (latter not shown).
10.1177_20363613231152333-fig1.jpg
PMC9869186_01_10.1177_20363613231152333-fig1.jpg
fig1-20363613231152333
Type 1 respiratory failure and massive right-sided pleural effusion. 20 years prior, she had been diagnosed with pelvic MPE involving the intradural filum terminale, with no other evidence of CNS infiltration on magnetic resonance imaging (MRI), and was treated with radical surgical resection. Three further isolated intra-pelvic recurrences were treated with repeated gross resection and adjuvant radiotherapy prior to the current presentation (Figure 1).
Histological and mutational characteristics of pleural disease. Histologically, this tumor comprises a mixture of papillary, solid and glandular architectures (A-D). The cells are arranged around variably well-formed fibrovascular cores (A and B), with prominent areas of myxoid stroma (A and C). Focal tumor necrosis is present (B). At higher magnification (D) the tumor is composed of cells with relatively small, bland, ovoid, vesicular nuclei with abundant fibrillary or focally clear cytoplasm. No pleomorphism or mitotic activity is discernible (hematoxylin and eosin). At low power (E), there is prominent papillary architecture with stromal cores being partly myxoid. A separate area (F) shows organoid nests of mildly atypical cells. Tumor cells stain diffusely for CD56 (G). Most tumor cells stain diffusely for S-100 (G). M-ethylation array profiling of pleural tissue (I) using the Illumina Infinium 850k EPIC array analysed as per the DKFZ Heidelberg algorithm, confirming myxopapillary ependymoma (MPE).
10.1177_20363613231152333-fig2.jpg
PMC9869186_01_10.1177_20363613231152333-fig2.jpg
fig2-20363613231152333
Pleural histopathology confirmed infiltration by malignant tumor with rosetting architecture composed of mainly cubo-columnar cells with fibrillary matrix, consistent alongside methylation array sequencing with the rare diagnosis of metastatic extra-CNS MPE (Figure 2).
Treatment response. (1) Carboplatin-etoposide. Disease progression (b) after three cycles of platinum-based chemotherapy is demonstrated, compared to baseline (a) (2) Temozolomide monotherapy. Disease progression (c) after six cycles of temozolomide is demonstrated, compared to pre-treatment (b). (3) Olaparib-Temozolomide combination therapy. Stable bulky thoracic disease (e) after 10 cycles of olaparib-temozolomide is demonstrated, compared to pre-treatment (d). (f) Plateau in rate of growth of target lesions by RECISIT 1.1 after commencement of olaparib-temozolomide.
10.1177_20363613231152333-fig3.jpg
PMC9869186_01_10.1177_20363613231152333-fig3.jpg
fig3-20363613231152333
Treatment continued to best response of stable disease (by RECIST and Choi criteria) for 12 cycles (Figure 3), and was then stopped due to declining performance status, specifically low appetite, fatigue and shortness of breath.