fig10

Figure 10. Atypical thymoma predominantly composed of oval to spindle cells (B3, spindle cell type) showing increased size of the cells, increased nuclear chromatin pattern, prominent nucleoli and scattered mitotic figures (60×). Tumors with these features are currently included under “atypical type A thymoma”, but it is also stated that it is not certain whether a pure spindle cell type of B3 thymoma could also exist and that the two would be “very difficult” to separate.