As determined by the microscopic histopathological appearances of their hematoxylin and eosin-stained samples,<unk> s are non-encapsulated nodular skin lesions that extend into the dermis. The lesions consist of a relatively disorganized and dense array of proliferating basophilic cells (i.e. cells appearing blue because of their abnormally large uptake of the hematoxylin stain). These cells are arranged as small cells with hyperchromatic nuclei and scant cytoplasm layered outside and larger cells with vesicular (i.e. vesicle-containing) nuclei layered inside of intertwining strips. Lymphocytes commonly populate these lesions. Some lesions may merge the histopathological features of<unk> s with those of cylindromas. Cylindromas are hair follicle tumors that consist of basal cells (i.e. small, round cells similar to those seen in the lowest layer of the skin's epidermis) which are arranged in ("jigsaw-like" cylindrical patterns separated by thickened basement membranes. The cylindroma tissues may also contain disorganized, dense arrays of proliferating basophilic cells.<unk> rcinoma tumors almost always derive from SA tumors and have areas of SA architecture abruptly transitioning to areas of SAC architecture. The SAC component of these lesions consists of cells that, along with their nuclei and cytoplasm, vary greatly in size and shape. The cells may be rapidly proliferating, have atypical mitosis figures, and may be invading nearby neural or lymphovascular structures; they do not arrange into intertwining strips of small and large cells. High-grade SAC tissues show a more severely disturbed architecture, more marked variation in cell, nuclei, and cytoplasm sizes and shapes, and more rapidly proliferating cells than low-grade SAC tissues. SAC tumor tissues may show various other features, e.g. they may closely resemble sarcomas. In rare cases, SAC has been reported to apparently arise de novo, i.e. begin as malignant lesions.
Spiradenoma
Dentigerous cyst
Hidrocystoma
Syringoma
Ganglion cyst
Paradental cyst
Mantleoma
Acrospiroma