The patient's symptoms settled so she was managed conservatively and the lesion resected at term at C-section.
Histopathology
Clinical History: Dermoid cyst. Removed at caesarean section.
Macroscopic: Oedematous Fallopian tube measuring 40 x 10mm with attached ovary/cyst measuring 110 x 90 x 75mm. On slicing, the cyst contains keratinous yellow material with hair. Small areas of orange brownish material ?haemorrhage. Some bony areas are also noted and a brown cystic area is identified measuring 15 x 8 x 9mm. The cyst appears biloculated.
Microscopic: The cyst shows areas of infarction. It is partly lined by keratinising squamous epithelium with underlying pilosebaceous units associated with a giant cell reaction most likely representing an inflammatory reaction to keratinous material. The wall consists of adipose tissue and some fibroconnective tissue with ovarian stroma. The appearances would be in keeping with a mature cystic teratoma (benign dermoid cyst) with areas of infarction. There are no immature elements and there is no evidence of malignant somatic transformation. The fallopian tube appears oedematous but otherwise shows no specific abnormality.
Conclusion: Right ovarian cyst - mature cystic teratoma (benign dermoid cyst). Right Fallopian tube - oedema.