Correct!
1. Relatives with a history of an inherited metabolic disorder
The hepatosplenomegaly and thrombocytopenia suggest a disorder infiltrating the bone marrow. These findings, in addition to the interlobular septal thickening, raise the possibility of a disorder that results in accumulation of abnormal tissue or cells in various organs, producing dysfunction of the affected organs. There are numerous such disorders, but many of them are heritable, and thus a history of family members with similar abnormalities would be strong evidence of a heritable metabolic disorder. The CT findings do not suggest hypersensitivity pneumonitis, nor would this diagnosis explain the historical and physical examination findings; therefore, choice “4” is not correct. The history of sandblasting should suggest the possibility of an occupational disorder, specifically pulmonary alveolar proteinosis. While the thoracic CT findings do not show a “crazy paving” pattern, the extensive, smooth interlobular septal thickening is not inconsistent with that consideration. However, the history and physical examination findings could not be explained by pulmonary alveolar proteinosis. As discussed previously, the CT findings, not to mention the history and physical examination findings, cannot be accounted for on the basis of smoking-related disorders. Finally, the history of a stem cell transplant would suggest the possibility of recurrent disease (often malignancy) that prompted transplant, disorders complicating the immunosuppression regimens used for stem cell transplant patients (particularly pulmonary infection), and disorders related to the nature of the transplant process (such as bronchiolitis obliterans or organizing pneumonia as manifestations of graft-versus-host disease). As noted above, thoracic CT features of pulmonary infection are not present in this case. Bronchiolitis obliterans and organizing pneumonia usually manifest on thoracic CT as bronchial wall thickening, bronchiectasis, and air trapping, and peripheral and peribronchial consolidation, respectively; these findings are not present in this case.
Further history did disclose other family members with a disorder similar to the patient’s complaints, although a clear diagnosis was not established.
Which of the following should be performed to establish the diagnosis for this patient? (Click on the correct answer to proceed to the next panel)