Cottoni F, Dell' Orbo C, Quacci D, Tedde G
Clinic of Dermatology, University of Sassari, Italy.
Am J Dermatopathol. 1993 Feb;15(1):77-81.
Primary osteoma cutis arises in the deeper dermis for no apparent reason and presents as mature, lamellar, and osteonic bone; secondary cutaneous osteomas are correlated with inflammatory processes, scars, or dysembryoplasia and are always composed of osteoid. Ultrastructural findings of primary cutaneous osteomas have not been reported to date. Light and electron microscopic findings of a case of primary osteoma cutis are described: mineralized areas may be divided into macrocalcification and microcalcification. Macrocalcification consists of lamellar bone. Osteocytes populate the lamellae, whereas collagen fibril distribution is bone-like. Hydroxyapatite deposition presents as globular or needle-like electron-dense material progressively masking the connective tissue matrix. Microcalcifications, which are found in macroscopically normal dermis around the calcified plaque, consist of osteoid tissue inhabited by osteoblast-like cells. Microcalcifications may be interpreted as metastatic calcifications related to the primary osteoma calcified plaque. Primary osteoma cutis may be considered as true bone amartothic formation rather than dermal mineralization.
原发性皮肤骨瘤在真皮深层无端发生，表现为成熟的板层状和骨单位骨；继发性皮肤骨瘤与炎症过程、瘢痕或胚胎发育异常相关，且总是由类骨质组成。原发性皮肤骨瘤的超微结构研究结果迄今尚未见报道。本文描述了一例原发性皮肤骨瘤的光镜和电镜研究结果：矿化区域可分为大钙化和微钙化。大钙化由板层骨组成。骨细胞分布于板层内，胶原纤维的分布类似骨组织。羟基磷灰石沉积表现为球状或针状电子致密物质，逐渐掩盖结缔组织基质。微钙化见于钙化斑块周围肉眼正常的真皮内，由类骨质组织构成，其中有类成骨细胞。微钙化可解释为与原发性骨瘤钙化斑块相关的转移性钙化。原发性皮肤骨瘤可被视为真正的骨错构瘤形成，而非真皮矿化。
