Review Question - QID 108618

This patient is a young female with a round, mobile mass that seems to respond to hormonal fluctuations, most likely a fibroadenoma, a benign mass common in reproductive aged women. In adolescents, the majority of lesions will diminish or completely resolve over time, so only reassurance and observation are required.

Classic fibroadenomas are relatively small (2-3 cm in size), in the upper outer quadrant of one or both breasts, and feel rubbery to palpation. They are generally painless but may become tender around the time of menses, as in this patient. There should be no skin changes, breast drainage, or lymphadenopathy. For an adolescent patient without concerning features or strong family history of premenopausal breast cancer in multiple first-degree relatives, there is no increased risk of malignancy from fibroadenomas. Fat necrosis is also a possible diagnosis in this softball player, as many patients do not recall a specific inciting trauma. However, given that the mass has been present for 2 months and undergoes hormonal changes, fibroadenoma is still the most likely diagnosis. Either way, the mass should eventually resolve and ultrasound is only indicated if the patient is older or there is persistence or change in the mass (Illustration A). Ultrasound is preferred in young women due to high breast density and the radiosensitivity of their tissues, but if the patient is over 35, mammography may also be performed. It would show a “popcorn” appearance (Illustration B). Upon confirmation of the diagnosis, either by imaging findings or core needle biopsy, surgical excision can be performed only if the patient experiences significant symptoms. Otherwise, routine follow-up is sufficient.

Illustration A shows an ultrasound of a fibroadenoma. The mass is ovoid and well-circumscribed with minimal internal complexities and an echogenic pseudocapsule, indicating that it is a benign finding. Illustration B shows the mammographic appearance of a fibroadenoma. There is a discrete oval mass that is hyperdense to the breast tissue with popcorn lobulations of the edges. Illustration C shows the mammographic appearance of a phyllodes tumor. There is a large and edematous mass that has smooth edges with a radiolucent halo.

Incorrect Answers:
Answer 1: Excision is usually not required for fibroadenomas given that they are not associated with increased risk of malignancy. If a patient feels the symptoms are too bothersome, surgical resection can be performed. If the diagnosis is called into question due to persistence or growth and there is concern for malignancy, excision may be required after imaging and biopsy are performed.

Answer 2: Oral contraceptives containing estrogen may increase, not decrease, the size of the fibroadenoma. Since these tumors are hormonally receptive, they often grow and become tender around the time of menses, during pregnancy, and with estrogen administration (as in an OCP). For this reason, they also typically regress in menopause.

Answer 3: Breast cancer risk is not increased by fibroadenomas, especially ones that are simple (no skin changes, drainage, lymphadenopathy, etc.), as in this patient. This patient’s family history of postmenopausal breast cancer in a second degree relative does put her at minimally higher risk of breast cancer, but this is unrelated to her fibroadenoma.

Answer 5: A rapid growth to over 5 cm suggests that the mass is actually not a fibroadenoma but a phyllodes tumor (Illustration C). This is a rare neoplasm that can be benign or malignant, and although most phyllodes tumors occur in older women, they have been reported in patients as young as 10 years old. They are known for their rapid increase in size within weeks and any such growth should be evaluated with ultrasound and core needle biopsy (and mammography if the patient is over 35). Given the malignant potential, wide local excision is the standard of care. Chemotherapy and radiation are generally not indicated as effectiveness is unclear.

Bullet Summary:
Fibroadenoma is a benign breast lesion that usually occurs in young females with a unilateral, mobile, well-circumscribed mass that is hormonally responsive. Reassurance and observation are the standard of care unless the mass persists, grows rapidly, or is present in an older woman, at which time ultrasound is indicated.