Lamella-particle complexes in the human placenta

Ribosome-lamella complexes in injured podocytes: description of a case and review of the literature

Ribosome-lamella complexes (RLCs) are mainly observed in a variety of hematological disorders and occasionally in solid neoplasms and in nonneoplastic diseases. These intracytoplasmic organelles are held to arise from rough endoplasmic reticulum, but, in agreement with more recent literature data, their function is still unclear. Ultrastructural analysis of glomeruli from a patient with focal segmental glomerulosclerosis secondary to metabolic syndrome disclosed significant foot process loss and abundant cytoskeletal proteins in major podocyte processes; two of the latter also displayed RLCs. This is the second report of RLCs in human renal glomerulus. Their close association with cytoskeletal proteins and lysosomes suggests a relationship with abnormal protein biosynthesis.

Ribosome-lamella complexes in the perineurial cells of neurofibromatosis

Ribosome-lamella complexes are occasionally seen in neoplastic disorders of the hematopoietic system, particularly in hairy cell leukemia. However, these structures are rare in epithelial and mesenchymal cells. In this report three tumors from a patient with neuro-fibromatosis (von Recklinghausen's disease) are examined by electron microscopy. Ribosome-lamella complexes were seen in the perineurial cells. This may be the first report of these complexes in nerve sheath tumors.

Ribosome-lamella complexes in intracranial tumours

A report is given of four intracranial tumours which contained ribosome-lamella complexes (RLCs). Three of the tumours were of neuroectodermal origin (two gangliogliomas and an astrocytoma), in which these structures have not previously been documented, and one was a haemangioblastoma. This study supports the view that RLCs may be related to abnormal protein synthesis.

Concentric membranous bodies in hepatocytes from a patient with systemic lupus erythematosus

Concentric membranous bodies (CMB) are described in the cytoplasm of hepatocytes in a liver biopsy from a patient with systemic lupus erythematosus (SLE). Histologically, the biopsy showed binucleated hepatocytes and rosette formation with lymphocytic infiltrates in portal fields. Hepatocyte cytoplasm showed focal fatty metamorphosis, focal staining for RNA with azure B at pH 4.0 (which was perchloric acid labile), diffuse alloxan-Schiff staining for protein, and PAS-positive, diastase-sensitive glycogen. By electron microscopy one to three CMB were present in 10-15% of hepatocytes. CMB appeared as concentric, "fingerprint" or parallel arrays of particle-studded, membranous profiles. Other membranous configurations included mazelike forms. The space of Disse was dilated. Bile ductular changes included basement membrane thickening and redoubling and luminal bulging of ductular epithelium devoid of microvilli. CMB have been rarely reported in human hepatoma and have not heretofore been observed in non-neoplastic human liver. Their appearance in hepatocytes in a patient with SLE may reflect an increase in protein synthesis during regeneration.