Type:
Educational Exhibit
Keywords:
Obstetrics (Pregnancy / birth / postnatal period), Oncology, MR, Diagnostic procedure, Cancer, Foetus
Authors:
N. Kinger1, P. Mittal2; 1Atlanta, GA/US, 2Decatur, GA/US
DOI:
10.26044/ecr2019/C-1462
Findings and procedure details
The magentic resonance imaging protocol for pregnant patients includes T2,
fat suppressed T2,
T1 precontrast,
in and out of phase,
diffuse,
and thin slice T2 images.
The most common tumors in pregnancy are generally benign and include fibroids,
corpus luteum cysts,
and desmoid tumors.
Plexiform Neurofibroma
- Peripheral nerve sheath tumor often seen in the setting of neurofibromatosis 1
- Plexiform neurofibromas are generally diffuse and involve deep nerves
- Benign but with malignant potential
MRI findings:
- T1 hypointense
- T2 hyperintense
Pregnancy:
- There is suggestion that pregnancy,
specifically increased progesterone and estrogen,
may result in increased size of the plexiform neurofibromas
Fig. 1: Plexiform Neurofibroma
Angiomyolipoma
- Benign lesion
- Most commonly seen in female adults
- Bleeding risk and as a result those greater than 4 cm are generally referred for treatment
- Can be sporadic or associated with phakomatoses such as tuberous sclerosis
MRI findings:
- Loss of hyperintense signal on fat suppression
- Drop out on out of phase imaging
Pregnancy:
- Angiomyolipomas are sensitive to hormones like estrogen and progesterone,
which are elevated during pregnancy,
resulting in increased size and potential for rupture
Fig. 2: Angiomyolipoma
Uterine Fibroids
- Benign
- Smooth muscle tumors of the uterus
- Pedunculated fibroids can be difficult to differentiate from adnexal masses
- Involution of larger fibroids during pregnancy is more likely to be complicated by internal hemorrhage,
necrosis and cystic degeneration,
which may be accompanied by pain and fever,
placental abnormalities,
vaginal bleeding or uterine rupture.
MRI findings:
- Variable
- T1 low to intermediate signal,
but can be T1 hyperintense if degenerating
- T2 low signal,
but can be T2 hyperintense if degeneration has occurred
Pregnancy:
- Fibroids are associated with miscarriage
- Increased estrogen can result in size of fibroids during pregnancy
Fig. 3: Uterine Fibroid
Fig. 4: Extensive Uterine Fibroids
Fig. 5: Cystic Degeneration of Intramural Fibroid
Desmoid Tumor
- Benign lesion
- Most commonly seen in females
- Fibroblastic tumors
- Most commonly seen in the abdominal wall,
root of mesentery,
and retroperitoneum
MRI findings:
- T1 hypointense
- T2 hypointense
Pregnancy:
- Can develop during pregnancy
- Increased estrogen seen during pregnancy can cause growth
Fig. 7
Umbilical Cyst/Hernia
- Most common type of ventral hernia
- Female predominance
- Can be acquired due to pregnancy,
obesity,
and ascites
MRI findings:
- Contents seen herniating through the ventral defect.
Pregnancy:
- Occurs secondary to increased intra-abdominal pressure
Fig. 8: Umbilical Cyst
Splenic Pseudocyst
- Benign lesion
- Are acquired/secondary
- Not lined by true epithelium
- Due to trauma,
infarction,
inflammation
- Can cause symptoms if large
MRI findings:
- T1 hypointense
- T2 hyperintense
Pregnancy:
Fig. 9: Splenic Pseudocyst
Corpus Luteum
- Benign lesion
- Follicular remnant that produces endocrine enzymes (estrogen and progesterone)
MRI findings:
- T1 hypointense
- T2 hyperintense with thick wall
Pregnancy:
- Grow in pregnancy and generally reach peak size around 10 weeks gestation
Fig. 10: Corpus Luteum
Peritoneal Inclusion Cyst
- Benign lesion
- Result from mesothelial proliferation secondary to inflammation
- Can present with pain
MRI findings:
- Irregular cystic lesion
- T1 hypointense
- T2 hyperintense
Pregnancy:
- Can be seen secondary to endometriosis,
which can worsen during pregnancy
- Can be mistaken for corpus luteum,
ovarian neoplasm,
or hemorrhagic cyst
Fig. 11: Peritoneal Inclusion Cyst
Hepatic Adenoma
- Benign lesion
- Feared complication is rupture into the peritoneal cavity and potential catastrophic hemorrhage.
Rupture is more common late in pregnancy and has associated maternal mortality of 44% and fetal mortality of 38%
MRI findings:
- Drops out on out of phase imaging
- T1 variable signal intensity
- T2 hyperintense
Pregnancy:
- Grow in pregnancy due to increased hormone levels
- Surgical excision or radiofrequency ablation is considered during pregnancy for adenomas greater than 5 cm or progressively enlarging adenomas
Fig. 12: Hepatic Adenoma
Ovarian Mature Cystic Teratoma (Dermoid Cyst)
- Benign lesion
- Most common ovarian neoplasm found during pregnancy
- Usually asymptomatic but can undergo torsion
MRI findings:
- Shows fat suppression or chemical shift artifact
- T1 heterogeneous
- T2 heterogeneous
Pregnancy:
Fig. 13: Ovarian Mature Cystic Teratoma
Breast Cancer
- Benign lesion
- Follicular remnant that produces endocrine enzymes (estrogen and progesterone)
MRI findings:
- T1 hypointense to fat and isointense to parenchyma
- T2 isointense or hypointense to parenchyma
Pregnancy:
- Increased hormones (estrogen and progesterone) increase stimulation of breast tissue and increase risk of malignancy
Fig. 14: Breast Cancer
Treatment:
- Surgery is often done during pregnancy
- Radiation therapy is often delayed until after delivery
- Chemotherapy is not given during the first three months of gestation
- Hormone therapy is often delayed until after delivery
Cervical Adenocarcinoma
- Second most common cervical cancer after squamous cell cancer
- Risk factors include HPV infection and multiparity
MRI findings:
- T1 isointense to pelvic muscles
- T2 hyperintense to cervical stroma
Pregnancy:
- Increased hormones (estrogen and progesterone) may increase risk of malignancy
Treatment:
- For low stage disease – conization
- For higher stage disease – delayed chemotherapy followed by surgery
Fig. 15: Cervical Adenocarcinoma
Epithelioid Neoplasm
- Rare soft tissue sarcoma
- Risk factors include HPV infection and multiparity
MRI findings:
- T1 isointense or hyperintense to muscle
- T2 heterogeneously isointense or hyperintense
Pregnancy:
- No definite association identified
Fig. 16: Epithelioid Neoplasm
Gastrointestinal Stromal Tumor (GIST)
- Most common sarcoma of the gastrointestinal tract
MRI findings:
- Often heterogenous due to necrosis
- T1 hypointense
- T2 hyperintense
Pregnancy:
- No definite known association
Treatment:
- For focal disease – surgery
- For metastatic disease – imatinib (although there is risk of teratogenicity particularly in first trimester)
Fig. 17: Gastrointestinal Stromal Tumor
Ovarian STUMP Tumor
- A smooth muscle tumors of uncertain malignant potential (STUMP)
- Rare
- Can be of ovary,
uterus,
or broad ligament
MRI findings:
- T1 isointense
- T2 hyperintense
Pregnancy:
- No definite known association
Treatment:
Fig. 18: Ovarian STUMP Tumor
Gastrinoma
- Endocrine tumor that can be seen in multiple endocrine neoplasia
- Results in ulcers and diarrhea which is termed Zollinger-Ellison syndrome
MRI findings:
- T1 hypointense to pancreatic tissue
- T2 hyperintense to pancreatic tissue
Pregnancy:
- No definite known association
Treatment:
Fig. 19: Gastrinoma
Cystic Mucinous Adenocarcinoma of the Retroperitoneum
MRI findings:
- T1 hypointense
- T2 hyperintense
Pregnancy:
- No definite known association
Treatment:
Fig. 20: Cystic Mucinous Adenocarcinoma of the Retroperitoneum