An unusual hotspot in a young woman with Hodgkin's lymphoma

Abstract

A young woman has started cancer treatment because of a Hodgkin's lymphoma. After four months of chemotherapy, a PET scan showed an unexplained hotspot in the right lower abdomen. This was later explained by an unsuspected pregnancy. Our case emphasizes the importance of a pregnancy test in all women in the reproductive age before starting cancer treatment. Haematologica 2008; 93:e14-e15 DOI: 10.3324/haematol.11849 Introduction Malignancy during pregnancy is thought to be extremely rare. However, in the USA, 1 of any 1000 pregnancies is accompanied by a malignancy.1 Similar to the incidence of malignancies of women in the reproductive age, the most common malignancies are of the cervix, breast and skin, and hematological malignancies e.g. leukemia and malignant lymphoma. The combination of malignancy and pregnancy is a major challenge for both the patient and the doctor. The choice of immediate treatment of the malignancy is often favorable for the pregnant woman but may be harmful for the fetus. Different treatment options are possible after diagnosing a malignancy during pregnancy, such as a therapeutic abortion, starting chemotherapy and/or radiotherapy while still carrying the fetus or postponing treatment until the baby is born. Few studies exist with conclusive outcomes about the risk for the (unborn) child of different treatment regimens for a malignancy in pregnant women. In general however, chemotherapy is contraindicated in the first trimester of pregnancy. 1,3We describe a young woman with an unusual hotspot on PET scan during treatment for a Hodgkin's lymphoma. The hotspot was later explained by an unsuspected pregnancy illustrating the importance of performing a pregnancy test in all women in the reproductive age before treatment of malignancies. Case reportAn 18-year-old woman was referred to our hospital after being diagnosed with nodular sclerosing Hodgkin's lymphoma stage IIA, localized in the mediastinum and neck. The planned therapy was four courses of ABVD chemotherapy followed by 30 Gray involved field radiotherapy. Four months after the start of ABVD-chemotherapy, an 18 F-deoxy-D-glucose (FDG) Positron Emission Tomography (PET) scan was made for re-evaluation. The PET scan showed no abnormal uptake at the originally involved sites, however an unexplained focal accumulation (hotspot) was found in the right lower abdomen (arrow). Six weeks later, the woman complained of abdominal distension. An ultrasound showed an unsuspected pregnancy with an estimated gestational age of 30 weeks. In retrospect, the hotspot reflected FDG accumulation in the fetal myocardium. The chemotherapy was given between the 8 th and 26 th week of gestational age. The PET scan was made in the 24 th week of gestational age. After 31 weeks of gestation, the patient developed a HELLP syndrome. A girl was born by caesarian section without congenital abnormalities. At 6 years of age, she apparently has a normal development. DiscussionOur case shows a very unusual clinical picture of a PET scan with a very intriguing outc...

Fetal Dose from PET and CT in Pregnant Patients

“…Angel et al (39) used Monte Carlo simulations to estimate fetal dose in CT for a range of gestational ages and patient sizes and found no significant correlation between gestational age and fetal dose. For various fetal ages and maternal body habitus, the fetal dose estimates were between 1.1 and 21.9 mGy for CT. F-FDG PET studies of pregnant patients are extremely uncommon, and even 18 F-FDG PET studies accidentally performed on pregnant patients are rare (6)(7)(8)(9)(10)(11). Because adequate and accurate data regarding 18 F-FDG uptake by the fetus are not available other than the very few case reports of accidental exposure, it is difficult to get an estimate of fetal radiation exposure from 18 F-FDG PET in pregnant patients.…”

“…Fetal dose estimates from CT have been based primarily on Monte Carlo simulations of geometric patient models (3)(4)(5). PET studies of pregnant patients are extremely uncommon, and even 18 F-FDG PET studies accidentally performed on pregnant patients are rare (6)(7)(8)(9)(10)(11). Therefore, providing fetal dose estimates from the CT and 18 F-FDG PET images themselves and from dose reports would be helpful to the medical imaging community.…”

The management of hodgkin lymphomas in pregnancies

“…Abdominal and pelvic CT is associated with an average effective radiation dose of 25 mGy. Few studies have reported fetal radiation exposure during PET‐CT examinations, but these have calculated fetal doses in the range of 1‐21 mGy, which is significantly lower compared to the above‐mentioned adverse fetal effects threshold dose. While the performance of neck and chest CT scan beyond first trimester can be considered reasonable, abdominal‐pelvic CT is usually not recommended, especially up to week 17 of pregnancy …”

Hodgkin’s Disease Staging by FDG PET/CT in a Pregnant Woman

“…Total fetal irradiation was ten times less than the 100 mSv malformative risk limit described by the International Commission on Radiological Protection [4,5]. Depending on the FDG PET/CT procedure and fetal age, the fetal estimated dose ranged between 1.01 and 21.9 mGy in the 12 other published cases of FDG PET/ CT carried out during pregnancy that we found in the literature (Table 1) [5][6][7][8][9][10][11].…”