Parathyroids are located in most cases adjacent but outside the thyroid. Therefore in serial sections we have to find sections where the lesion in suspicion is not covered with thyroid parenchyma. Among the images presented above, longitudinal section 2 and 3 fulfill this criteria. Naturally, this is not a decisive sign because a thyroid nodule located next to the capsule of the thyroid has a similar presentation. On the other hand, if we cannot find even one view where a lesion is not covered with thyroid parenchyma then the likelihood of parathyroid origin is negligible.