Table 1.
The clinicopathologic features for 14 cases of anaplastic myxopapillary ependymoma. Cases are ordered by age of presentation (eight pediatric cases followed by six adult cases). More than one size or location is listed for cases with recurrences, separated by commas. The term “initial” is used to indicate the initial resection, a first recurrence is denoted as 1st, a second recurrence is denoted as 2nd. Features considered anaplastic are highlighted in green. Yellow boxes indicate the presence of necrosis that occurred after radiation or chemotherapy, and therefore was not considered an anaplastic feature; this is also indicated by an asterisk. Involvement of the adjacent tissue was assessed by histologic and/or radiographic findings. In cases with a large tumor size and direct invasion of the adjacent bone or soft tissue (case #12 and #10), the integrity of the tumor capsule would be lost. In cases with bone erosion, bone remodeling, involvement of sacral rootlets, involvement of dura or an entrapped ganglion, this was not taken as a direct indication of capsule integrity. M: male, F: female, MVP: microvascular proliferation, HPF: high power fields, STR: subtotal resection, GTR: gross total resection, Res: resection in which gross total or subtotal resection was not specified, XRT: radiation therapy, pXRT: partial course of radiation therapy, Chem: chemotherapy, C: cervical, T: thoracic, L: lumbar
| Case # | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age at MPE diagnosis in years, (age at anaplasia diagnosis, if later) | 6 | 7 | 10 | 10 | 11 | 12 | 13 | 16, (20) | 31, (32) | 31, (45) | 40 | 45, (57) | 50 | 55 |
| Gender | F | F | M | M | M | M | M | F | M | F | F | M | M | F |
| Location | L4-S1 (intradural) | T12-L3 (intradural) | S1-S2 (intradural) | L1-L2 (intradural, centered at conus medullaris) | filum terminale (L4–5, S2–3) and S1 nerve root (3 masses) (intradural) | lumbar mass, lumbar and sacral (intradural) | L1-L2 with multiple smaller lesions (posterior fossa, C, T, and L cistern) (intradural) | L3-L4 & L5-S1, multiple T and L lesions (intradural) | sacral filum terminale region mass with smaller T lesions (intradural) | sciatic notch, pelvic & sciatic masses (unclear if MPE was a primary soft tissue form) | floor of 4th ventricle | T11-L2, L1, T8-L5 (originally an intradural mass filling the thecal sac) | L5-S3 (intradural) | L1-L2, L2 (intradural) |
| Size | size not specified | not specified | 4.2 cm | 4.5 cm | 3 cm mass on imaging | 3.2 cm, 1.5 and 1 cm | main mass 3.8 cm | 1.7 and 1.0 cm, multiple (up to 1.6 cm) | not specified | initial size not known, 10 cm and 5.5 cm | 5 cm | 11.5 cm, 10 cm, size of second recurrence not specified | 8.5 cm | 2.7 cm, 2.3 cm |
| Ki-67 LI (data source) | 20% (initial resection) | 11% (initial resection) | 34% (initial resection) | 15% (initial resection) | 14% (initial resection) | 10%, 17% (initial resection, 1st recurrence) | 8% (initial resection) | 10% (1st recurrence) | 10% (9m re-resection) | 40% (1st recurrence) | 20% (initial resection) | 26% (1st recurrence) | 10% (initial resection) | 20% (initial resection) |
| Mitotic Index per 10 HPF | 12 | 10 | 20 | 6 | 5 | 3, 2 | 6 | 6 | 7 | 7 | 5 | 17 | 14 | 7 |
| Necrosis | Yes | No | Yes: focal non-palisading | No | Yes: non-palisading | Yes: palisading (only on recurrence) | No | No | * Yes: non-palisading and palisading | * Yes: non-palisading and palisading | Yes: focal non-palisading | * Yes: non-palisading | Yes: non-palisading and palisading | Yes: non-palisading |
| MVP | Yes | Yes | Yes | Yes: small foci of MVP | Yes: multiple foci | Yes (initial and recurrence) | Yes | No | Yes | Yes | Yes | Yes: prominent | Yes: extensive | Yes |
| Onset of anaplastic features | initial resection | initial resection | initial resection | initial resection | initial resection | initial resection | initial resection | recurrence | present on recurrence/second surgery at 9 months | first recurrence | initial resection | first recurrence | initial resection | initial resection |
| Treatment | GTR, proton therapy | STR, XRT | GTR, proton therapy | GTR, XRT | GTR | Initial: GTR 1st: GTR, XRT | STR, XRT | Initial: GTR 1st: Res, XRT | Initial: STR, Chem, pXRT 1st: STR | Initial: Res, XRT 1st (pelvic mass): GTR (sciatic mass): GTR, Chem | STR, proton therapy | Initial: STR, XRT 1st: GTR 2nd: GTR, XRT | GTR, XRT | Initial: GTR, XRT 1st: unspecified |
| Recurrence/Metastasis status | none reported within 2 yrs | stable residual disease ~1.5 yrs | none reported within 1 yr | none reproted within 4 months | none reported within 1 month | 1st: 1 yr, nothing additional reported over the following 6 yrs | stable residual disease at 4 yrs | recurrence at 4 years | lost to clinical follow-up after 2 years, patient died at age 36, no autopsy | 1st: 14 yrs Lung metastasis: 14 yrs patient died at age 48 | none reported within 2.5 yrs | 1st: 12 yrs 2nd: 15 yrs patient died 16 yrs after diagnosis, age 60 with extensive local disease | none reported within 9 yrs | 1st: 18 months, no subsequent clinical follow-up available |
| Documented recurrence after anaplasia | N/A | N/A | N/A | N/A | N/A | recurred once after anaplasia | N/A | N/A | N/A | one additional surgery after anaplasia was diagnosed, both masses were present at 14 yrs, surgeries were separated by 4 months | N/A | recurred once after anaplasia | N/A | recurred once after anaplasia |
| Involvement of adjacent tissue by histologic and/or radiographic findings | No | No | Yes: sacral bone erosion but not invasion, entrapped ganglion | No | No | Microscopic dural invasion, no signifigant involvement of adjacent tissues | No | No | No | Yes: invasion of adjacent soft tissues | No | first recurrence destroyed L1 vertebrae, extended into paraspinal tissues, just prior to death imaging showed a large soft tissue mass invading L2-L4 veterbral bodies, extending into paraspianal and left psoas muscles | Yes: involvement of sacral rootlets and dura, with sacral bone remodeling (cortical thinning and destruction without invasion) | No |
| CSF dissemination | No | No | No | No | No | Yes | Yes | Yes | Yes | Yes: found 14 yrs after initial | No | Y: at time of recurrences | suspected drop metastasis | Yes |