Managing prenatally diagnosed asymptomatic congenital cystic adenomatoid malformation

To review our cases of congenital cystic adenomatoid malformation (CCAM) with special emphasis on the management of prenatally diagnosed asymptomatic CCAM (PDA-CCAM).

A total of 42 consecutive CCAM patients treated between 1990 and 2008 at our institution and affiliated hospitals were divided into four groups, according to whether prenatal diagnosis was made [PD (+) or (-)], whether patients were symptomatic [S (+) or (-)], whether there was any increase in size observed radiologically [R (+) or (-)], and whether surgical resection was performed [X (+) or (-)], to give a symptomatic early surgery group diagnosed prenatally (group A; n = 15): PD (+), S (+), R (+), X (+); an asymptomatic early surgery group diagnosed prenatally (group B; n = 8): PD (+), S (-), R (-), X (+); a conservative observation group diagnosed prenatally (group C; n = 6): PD (+), S (-), R (-), X (-); and a symptomatic surgery group diagnosed postnatally (group D; n = 13): PD (-), S (+), R (unknown), X (+). Patient demographics, effects of surgical stress, histopathology, and outcome were compared between the four groups.

Groups A and B had surgery as neonates and mean duration of post-operative follow-up has been 15.7 months for group A and 63.3 months for group B. Group C has been under observation for a mean of 21.6 months (range: 10-40 months) with no incidence of infection. In group D, four had surgery as neonates after developing respiratory distress, and nine had surgery later (mean age: 4.1 years) after developing pneumonia (late onset group). Mean duration of follow-up for group D has been 48.0 months. In the late-onset group, pneumonia was successfully treated medically, and all nine had elective surgery with no intra- or post-operative complications. However, compared with group B (asymptomatic early surgery group diagnosed prenatally) the late-onset group had significantly longer duration of surgery (P < 0.05), significantly greater intraoperative blood loss (P < 0.01), and significantly higher peak post-operative C-reactive protein (P < 0.01), although there were no statistical differences for increase in white blood cell count ratios or length of hospitalization. Malignancy has not developed to date in any subject.

Our data suggest that patients with PDA-CCAM may be observed safely until they become symptomatic or changes in size are observed radiologically.