| sigmoideia | singular | singular | |
| sigmoideias | singular | singular | |
| sigmoideiazinha | singular | singular | |
| sigmoideiazinhas | singular | singular | |
| sigmoideinha | singular | singular | |
| sigmoideinhas | singular | singular | |
| sigmoideu | singular | singular | |
| sigmoideus | singular | singular | |
| sigmoideuzinho | singular | singular | |
| sigmoideuzinhos | singular | singular |