gms | German Medical Science

Objectives: Spinal lesions can be the initial presentation in 20% of patients (pt) with a prior unknown cancer. The initial diagnosis carries significant treatment, prognostic and emotional weight, especially when spinal intervention is inevitable due to pathologic fracturing or metastatic spinal cord compression. Histopathological (HP) examination represents the diagnostic gold standard, with one downside, it can take up to 14 days due to decalcification of bony samples. Intralesional aspiration cytology (IAC) in spine surgery, so far, is not performed routinely despite its potential for quicker differentiation between hematologic or solid neoplasia. We introduced supplementary IAC in a multidisciplinary approach aiming to shorten time to diagnosis (Figure 1 [Fig. 1]).

Methods: Standard procedure for pt presenting with prior unknown cancer and a malignant spinal lesion requiring spine surgical intervention was adapted in 2020 to include intraoperative IAC via transpedicular Jamshidi biopsy. HP specimen collection and analyses were performed standardized. Cytologic specimens were evaluated using May-Gruenwald-Giemsa stain by a board-certified pathologist. Retrospectively statistical analysis was performed using the student's t-test and Cohen's kappa to interpret concordance.

Results and conclusion: To date, 50 consecutive pt (38% female) with a median age of 64 years (range 20-84) were included. 4 pt showed no evidence of malignancy. Multiple myeloma (incl. plasmacytoma) and solid neoplasia (Table 1 [Tab. 1]) were HP diagnosed in 25 and 66 % respectively. One pt presented with B-cell lymphoma.

Time to confirmation of the diagnosis using cytologic diagnostics was 1.8 d (1.8 standard deviation (SD)), whereas HP results were received after 8.8 d (3.5 SD; p < .01). In 4 pt, with cytologic evidence of adenocarcinoma and highly elevated prostate-specific antigen in serum, specific systemic treatment with bicalutamide could be initiated in mean 7 days (d) before HP confirmed prostate carcinoma. In six further cases therapy could be induced, in mean, 3 days earlier. Concordance between HP and IAC was 0.922 (kappa) with respect to detection of malignant cells and differentiation between hematologic or solid neoplasia. In one case scarce material led to inconclusive IAC, in another case, HP diagnostic failed to detect myeloma.

Very high concordance should allow safe implementation in the setting of oncologic spinal surgery. Even further, IAC improved patients' guidance due to prompt initiation of specific diagnostic steps and individualized treatment planning. IAC should be implemented routinely in addition to HP diagnostic to improve patient care in a multidisciplinary team.