Organoid (hypermature) ovarian teratomas: Report of four cases, one of which harbored a well-differentiated neuroendocrine tumor.

Organoid (hypermature) teratomas are highly specialized teratomas showing organ formation, most frequently from the digestive tract or bronchial wall. We present four cases of ovarian organoid teratomas, one with a distinguishable mandible with teeth, one with small intestine, one with large intestine containing a well differentiated neuroendocrine tumor and another with both large intestine and bronchial wall. These tumors have a distribution similar to conventional teratomas and usually behave benignly, although cases of malignancy have been reported.