Abdominal mass in a pregnant woman forces induction
Figure 1. The nontender, immobile mass measured 21 cm.
Mrs. Q, aged 33 years, was a stay-at-home mother of three and pregnant with her fourth child. At 30 weeks' gestation, a routine ultrasound was performed to evaluate growth, as her third child weighed more than 9 lbs at delivery. Although ultrasound revealed normal growth, an incidental finding of a large mass in the patient's left upper quadrant was noted.
Mrs. Q had not traveled internationally and reported no weight loss, fevers, night sweats, or pain. Her medications were levothyroxine and prenatal vitamins. Medical history was significant for hypothyroidism and three dilation-and-curettage procedures secondary to miscarriages. She had no history of tobacco, alcohol, or illicit-drug use. There is no family history of cancers or other disorders.
1. Physical exam
Mrs. Q's vital signs were BP 141/75 mm Hg, heart rate 69 beats per minute, respiratory rate 14 breaths per minute, weight 179.4 lbs. No adenopathy was appreciated. Skin was pink, warm, and dry. Auscultation revealed a regular heart rate and rhythm. Lungs were clear to auscultation. Abdomen was rounded secondary to pregnancy, with fetus head palpated at the right-lower-quadrant region. The left upper quadrant revealed a large, nontender, immobile mass, which measured approximately 21 cm.
Mrs. Q's workup included a complete blood count, comprehensive metabolic panel, cancer antigen 19-9, cancer antigen 125, carcinoembryonic antigen, lactate dehydrogenase, chromogranin A, erythrocyte sedimentation rate, immunoglobulins, and beta2 microglobulin. All were within normal limits.
Abdominal MRI was read initially as a mass consistent with possible ovarian source. After a second reading, it was decided the mass was most consistent with a solid pseudopapillary tumor of the pancreas. Two biopsies were deemed inconclusive.
The differential diagnoses included: lymphoma, GI stromal tumors, pancreatic cancer, ovarian cancer, fibrosarcoma, and neuroendocrine cancer. Mrs. Q developed pancreatitis and was admitted to the hospital. It was decided to induce labor, and she delivered a healthy boy at 34 weeks' gestation. After delivery, she underwent a tumor resection, distal pancreatectomy, splenectomy, partial gastrectomy, and omentectomy. The tumor measured 21 cm (Figure 1), and final margins were negative after re-excision. Final pathology revealed desmoid fibromatosis.
The term desmoid comes from the Greek word demos, which means tendonlike. Desmoid tumors are twice as common in women as in men. These growths are rare (two to four per million population per year). They are typically found in individuals aged 10 to 40 years but can occur at any age.
Definitive diagnosis can only be made by histological examination from a biopsy. Desmoid tumors have a benign histologic semblance with a negligible metastatic scope. Formerly known as "fibrosarcoma grade I," desmoid fibromatosis has also been called "aggressive fibromatosis." These tumors do tend to be aggressive in nature and have high rate of recurrence, even after complete resection. Desmoids can lead to infiltration, causing pressure effects and obstruction, which lead to an increase in morbidity and mortality.
Gardner syndrome occurs when desmoid tumors are associated with familial polyposis and the adenomatous polyposis coli (APC) gene mutation. They have also been associated with mutations in the beta-catenin gene and trisomy 8 and 20. These desmoid tumors tend to have a higher incidence for recurrence. A proliferative response to estrogen has been proven in fibroblasts. Fibroblasts have been associated with such high-estrogen states as pregnancy and most commonly arise in the anterior abdominal wall but can occur in other regions as well.
Surgical removal with negative margins is the mainstay of treatment. If surgery is not an option, then radiation and pharmacologic therapy with antiestrogens and prostaglandin inhibitors can be used. In recurrence, such chemotherapy regimens as doxorubicin, decarbazine, and carboplatin may be effective.
Mrs Q's workup will include a colonoscopy to evaluate for familial adenomatous polyposis; DNA sampling to look for single-strand conformation polymorphism; and analysis of beta-catenin, H-ras, K-ras, N-ras, APC, and p53 genes using polymerase chain reaction.
Thankfully, Mrs. Q's mass was found before it caused further harm. In the growing field of genetics, the implications for screening are growing by leaps and bounds. A desmoid tumor is very rare and must be followed-up with diligence. Mrs. Q is currently doing very well and enjoying the new addition to her family.
Ms. York is an oncologic nurse practitioner at Rose Oncology Medical Center in Denver.
Soravia C, Berk T, McLeod RS, Cohen Z. Desmoid disease in patients with familial adenomatous polyposis. Dis Colon Rectum. 2000;43:363-369.
All electronic documents accessed April 15, 2011.