Light chain deposition disease masquerading as smoking-associated nodular glomerulosclerosis with deposits identified by electron microscopy only.

Light chain deposition disease (LCDD) is a form of monoclonal gammopathy of renal significance. The diagnosis is based on the immunofluorescence (IF) findings of linear monoclonal light chain staining of basement membranes throughout the kidney, which appear as non-organized, granular punctate to powdery electron dense deposits by electron microscopy (EM). Although "LCDD by IF only" without EM deposits has been well-described, LCDD identified by EM with negative IF is very rare and hardly mentioned in the literature. Herein we describe a case of lambda-type LCDD that appeared negative by IF and showed light microscopic findings of nodular glomerulosclerosis, which was initially attributed to the patient's history of significant tobacco use and uncontrolled hypertension. However, EM later showed powdery electron dense material in focal glomerular and tubular basement membranes and mesangium. Subsequent bone marrow analysis revealed greater than 60% lambda-restricted plasma cells. We report this case to illustrate that within the differential diagnosis of nodular sclerosis, monoclonal immunoglobulin deposition disease (MIDD) should remain in the differential even if immunofluorescence appears negative as EM can prove to be crucial in identifying cases of MIDD.

Atrial septal defect can be easily missed in chromosome 18q deletion syndrome.

The frequency of 18q- is estimated to be approximately 1/40 000 live births and is more commonly associated with certain clinical features including short stature, intellectual disability and malformations of many major organ systems. Congenital cardiac abnormalities are present in 24-36% of cases and screening can prove difficult. A 28-year-old Caucasian female with a history of long arm chromosome 18q deletion was evaluated for persistent dyspnea and decreased activity level. Multiple hospitalizations failed to identify the etiology of her symptoms. Initial transthoracic echocardiogram failed to show any underlying cardiac etiology of her symptoms. Multiple recurrent hospitalizations with the same chief complaint. A transesophageal echo (TEE) showed large secundum atrial septal defect (ASD). Successful surgical closure of her large secundum ASD provided significant symptoms relief. The threshold of obtaining TEE should be low in patients with 18q- which permits early recognition and treatment of underlying structural heart disease.