Dystrophic and psammomatous calcifications in a desmoid tumor. A light microscopic and ultrastructural study

Abstract

A desmoid tumor occurring in the abdominal wall of a 6‐year‐old boy with extensive microcalcifications was documented. Two forms of calcifications were observed: an irregular, amorphous dystrophic calcification of the collagen fibers and an organized, laminated psammomatous calcification (psammoma bodies). Ultrastructural studies revealed that the dystrophic calcification is a result of direct mineralization of individual collagen fibrils with subsequent coalescence to form large, calcified masses. Psammomatous calcification tended to cluster around areas where the collagen fibers assumed a whorled configuration. It is suggested that the circular orientation of the collagen fibers in some way favors the laminar deposition of hydroxyapitite crystals. The cause of the pathologic calcifications is the presence of extensive amorphous eosinophilic degeneration of the collagen fibers.

Fibroblastic and Myofibroblastic Tumors in Children and Adolescents

“…Atrophic entrapped muscle fibers may simulate cellular pleomorphism. Dystrophic calcifications are infrequent [339]. Recurrent lesions show identical morphologic features, although extensive collagenization secondary to scarring may render distinction difficult between the desmoid and a surgical scar.…”

Diffuse and psammomatous calcification in intestinal type gastric carcinoma: Report of two cases with literature review

“…Correspondingly, psammoma bodies as well as accompanying hyaline globules seen in some cases of gastric adenocarcinomas were considered as degenerative changes of neoplastic cells by some authors (11). It has been suggested that psammomatous calcification in meningioma and desmoid tumor is a result of direct mineralization of round, whorled collagen bodies, which have been suggested as the precursor lesion of psammoma bodies (27,28). It has also been proposed that the initial foci of mineralization in psammoma bodies are extracellular matrix vesicles derived from cellular degeneration with hydroxyapatite within matrix vesicles by ultrastructural study of psammoma bodies in meningocytic whorl (29).…”

“…It has also been proposed that the initial foci of mineralization in psammoma bodies are extracellular matrix vesicles derived from cellular degeneration with hydroxyapatite within matrix vesicles by ultrastructural study of psammoma bodies in meningocytic whorl (29). Mitochondria ha- ve been considered then as the initial focus of intracytoplasmic calcification (28). However, ultrastructural observation of needle-like crystalline deposits other than mitochondrial calcification was made by several investigators, particularly in papillary carcinoma of the endometrium, duodenal carcinoma and non-mucinous carcinoma of the stomach (6,16,30,31).…”

As You Like It, Part 3: A Critique and Historical Review of Calcification as Seen with the Electron Microscope

“…About calci cation in the desmoid tumor Lee and Sen [ 45 ] state that calci cation was found to be à`r esult of direct mineralization of individual collagen brils´´and``it is clear that matrix vesicles were not involved in this instance.´Á s is well known, in meningioma, psammoma bodies form in meningiocytic whorls. The periphery of the meningiocytic whorl comprises a shell of meningiocytic cells and the center contains structures, such as the basal lamina ( or fragments thereof ), a whorl or a mass of collagen brils ( this is the principal component ), proteoglyca n particles, and occasionally also preelastic or elastic bers.…”