Correct!
2. Abdominal fat aspirate
An endomyocardial biopsy could be performed to obtain a definitive diagnosis from the thickened left ventricle, but is needlessly invasive given the information known so far as well as the fact that less invasive sampling may be capable of establishing the correct diagnosis. Similarly, video-assisted thoracoscopic lung biopsy could effectively sample the lung parenchymal abnormalities but is also needlessly invasive. 18FDG-PET scanning can neither confirm nor exclude a particular histopathologic diagnosis; rather, 18FDG-PET scanning may disclose sites of metabolically active potential disease, which may be useful for prioritizing interventions. However, there are several organs that have already been shown to be abnormal and there are biochemical data pointing to a diagnosis, and therefore 18FDG-PET scanning is not needed to search for additional sites of disease for intervention. Furthermore, a number of disorders may not show metabolic activity at 18FDG-PET scan, and therefore the presence of absence of PET scan abnormalities would not be management-altering for this patient. CT sialography can be useful for assessing salivary duct calculi and other abnormalities affecting the salivary duct system. While the patient was reported to have submandibular gland enlargement, this finding reflects involvement of her systemic disorder and not the result of salivary duct obstruction.
The patient underwent serum protein electrophoresis showed an “M” spike measured at 1.9 gm/dL and immunofixation confirmed the presence of a monoclonal IgG lambda protein. A fat pad aspirate stained positive for Congo red. A radiographic skeletal survey showed no lytic or osteoblastic lesions.
Which of the following diagnoses is most likely to be the correct diagnosis for this patient? (Click on the correct answer to be directed to the ninth and final page)