A 19-year-old healthy Indian female noted blurred vision, redness, and pain in the right eye (RE) for 6 months. On examination, visual acuity (VA) was counting fingers in RE and 20/20 in left eye (LE). The RE demonstrated shallow anterior chamber with 360 degrees peripheral anterior synechiae. Approximately 400 translucent spherules of 50-200 micron diameter were embedded in the iris stroma and anterior chamber angle [Fig. and ]. Other findings included posterior subcapsular cataract, elevated intraocular pressure (IOP) of 30 mm Hg, and advanced glaucomatous damage with C:D ratio of 0.9:1. The LE was normal. Iris biopsy demonstrated acellular, amorphous hyaline deposits within the iris stroma, weakly staining with Congo red, suggestive of amyloid []. Transmission electron microscopy (TEM) confirmed amyloid fibrils []. Results of analysis with in situ hybridization for subtyping were inconclusive due to the presence of heavily melanized melanocytes. Systemic evaluation including complete blood count, liver and kidney function tests, serum and urine protein electrophoresis, serum and urine light chain protein, bone marrow biopsy, and PET CT scan were normal. Over the following 3 years, the patient developed cataract, uncontrolled glaucoma, and corneal decompensation, requiring cataract surgery, glaucoma valve surgery, and penetrating keratoplasty, with final VA at 20/30 in affected eye [Fig. and ].
A 60-year-old man with history of left nephrectomy for clear cell renal cancer (stage I) and resected colorectal adenocarcinoma (stage II) presented with a pulmonary mass lesion in the left upper lobe on surveillance imaging. Transaxial CT (B) revealed a 2.9 cm slightly lobulated lesion in the inferior lingular segment of the left upper lobe overlying the left oblique fissure. 18-F FDG PET/CT images (A, C, D) demonstrated moderate to marked FDG avidity (SUVmax 6.4) in this lesion.\nHistopathology of CT-guided core needle biopsy showed tumour cells with relatively uniform nuclear and clear cell cytoplasm with positive staining for PAX8 and renal cell antigen, consistent with metastatic renal cell carcinoma. The patient underwent wedge resection of the left upper lobe metastasis with clear excisional margins.\n6 months later, follow-up imaging with 18-F FDG PET/CT and diagnostic CT was performed. Transaxial CT (B) demonstrated a slowly enlarging subcentimeter 9mm pulmonary nodule in the right upper lobe. Maximum intensity projection, transaxial fused PET/CT and transaxial PET (A, C, D) images demonstrated moderate FDG avidity (SUVmax 4.6 on current PET, SUVmax 2.4 on previous PET (not shown)) in this lesion. No other suspicious FDG avid focus was detected. Given the proven pulmonary metastatic disease from renal cell cancer, further small volume oligometastatic disease was suspected. Reliable needle biopsy of the lesion was considered difficult due its small size and deep location. The patient subsequently underwent segmental resection of this sub centimeter pulmonary nodule.\nHistopathology of the second pulmonary nodule demonstrated no evidence of malignancy. Instead, there was amorphous hyaline acellular amyloid-like material associated with a rim of multinucleated inflammatory cells (). The chronic inflammatory cells comprised mainly of mature plasma cells with smaller numbers of lymphocytes. Crystal violet stain was positive, and the Congo red stain demonstrated focal birefringence, confirming nodular pulmonary amyloidosis. The patient continues to be under observation for further tumour recurrence.