Application of a quick-freezing and deep-etching method to pathological diagnosis: a case of elastofibroma

Abstract

A case of elastofibroma in a middle-aged Japanese woman was examined by the quick-freezing and deep-etching (QF-DE) method, as well as by immunohistochemistry and conventional electron microscopy. The slowly growing tumor developed at the right scapular region and was composed of fibrous connective tissue with unique elastic materials called elastofibroma fibers. A normal elastic fiber consists of a central core and peripheral zone, in which the latter has small aggregates of 10 nm microfibrils. By the QF-DE method, globular structures consisting of numerous fibrils (5-20 nm in width) were observed between the collagen bundles. We could confirm that they were microfibril-rich peripheral zones of elastofibroma fibers by comparing the replica membrane and conventional electron microscopy. One of the characteristics of elastofibroma fibers is that they are assumed to contain numerous microfibrils. Immunohistochemically, spindle tumor cells showed positive immunoreaction for vimentin, whereas alpha-smooth muscle actin, desmin, S-100 protein and CD34 showed negative immunoreaction. By conventional electron microscopy, the tumor cell had thin cytoplasmic processes, pinocytotic vesicles and prominent rough endoplasmic reticulum. Abundant intracytoplasmic filaments were observed in some tumor cells. Thick lamina-like structures along with their inner nuclear membrane were often observed in the tumor cell nuclei. The whole image of the tumor cell was considered to be a periosteal-derived cell, which would produce numerous microfibrils in the peripheral zone of elastofibroma fibers. This study indicated that the QF-DE method could be applied to the pathological diagnosis and analysis of pathomechanism, even for surgical specimens obtained from a patient.

Benign tumors of the chest wall

“…Negativity is found for S100, desmin, smooth muscle actin, p53 ( 105 ). The ultrastructural examination discloses central core contains mature fibers and cylinders composed of immature amorphous elastic tissue ( 106 , 107 ). Molecular biological analysis revealed Xq12-q22 or #19 gains in 30% of the cases ( 108 ).…”

Chondrosarcoma with Myxoid Change: A Study Using a Quick-freezing and Deep-etching Method

“…Both methods were previously documented in our reports [1,2,5,11]. The prepared replica membranes and ultrathin sections were observed in an electron microscope (JEM-1200EX, JEOL, Tokyo, Japan), and photographed at various magnifications.…”

“…To observe surgical specimens obtained from patients, we are using a quickfreezing and deep-etching (QF-DE) method, which is an advanced electron microscopic technology [1][2][3][4][5]. With this method, soluble proteins in the cytoplasm and extracellular matrix are not suitable for observation because they are removed in the course of the preparation procedure.…”