Rushton bodies.

Rushton bodies (RBs) are hyaline bodies found in epithelial lining of the odontogenic cysts that appear as peculiar, eosinophilic, straight or curved, irregular or rounded, polycyclic glassy structures occurring with variable frequency in the epithelial lining of odontogenic cysts. This article depicts the various shapes and amusing staining properties of RBs along with a brief cognizance about their much-debated origin. Copyright:

RUSHTON BODIES

Rushton bodies (RBs) were originally observed by Dewey (1918) as hyaline bodies and mentioned in literature by Lund in 1924.[1] However, they were described in detail by Rushton (1955) as hyaline bodies found in epithelial lining of the odontogenic cysts that appear as peculiar, eosinophilic, straight or curved, irregular or rounded, polycyclic glassy structures occurring with variable frequency in the epithelial lining of odontogenic cysts.[2]

Published studies suggest an incidence of 10% in radicular cysts followed by dentigerous cyst (4%–10%) and odontogenic keratocysts (7%).[2] Although these are restrictedly expressed in odontogenic cysts, one case of plexiform ameloblastoma was reported by Takeda et al. in 1985. Present case demonstrates the presence of RBs in the radicular cyst. [Figures 1–3].[3]

Figure 1

Photomicrograph showing Rushton bodies of linear, circular and lamellated pattern as acellular, eosinophilic structures in the epithelial lining of the radicular cyst (×4)

Figure 3

Corresponding hand drawn illustration of Rushton bodies

Hematoxylin and eosin-stained Rushton bodies (×10)

MORPHOLOGY

Rushton described hyaline bodies in three different morphologic patterns as linear, straight, or curved into various figures, often in a double strip as if an oval has been completely flattened with a little granular material at its center or like a hairpin [Figure 1], some resembling broken up pieces of plate and lastly circular or polycyclic agglomerations which are occasionally laminated.[2]

ORIGIN

A series of theories have been contemplated regarding the origin of RB. However, the origin of these hyaline bodies remains unsolved.

Odontogenic epithelial origin

Rushton (1955) and Wertheimer (1962) suggested through their analysis that these hyaline bodies resembled secondary enamel cuticle of Gottlieb and keratin or keratin-like substance.[14] Kulkarni et al. found RBs to be similar to dental cuticle but different from keratin.[5] Philippou et al. in 1990 put forward/suggested that hyaline bodies are a product of odontogenic cyst epithelium.[6]

Morgan and Johnson and Allison concluded that hyaline bodies are formed as a consequence of consecutive secretory effect/activity of odontogenic epithelium.[78]

Hematogenous origin

Bouyssou and Guilhem and Sedano and Gorlin believed that RBs are derived from the thrombi in the varicose venules as they exhibited histochemical reactivity for hemoglobin.[910] Hodson (1966) proposed RBs to be composed of denatured hemoglobin following positive tannic acid phosphomolybdic acid (TP) A reaction.[1] El-Labban suggested RBs to be originating from degenerating red blood cells.[11] Browne and Matthews detected fibrinogen within the cores of some circular and polycyclic forms, suggesting their formation as reaction to extravasated serum.[12] However, Dent and Wertheimer refuted the hematogenous origin theory for RBs as they did not observe histochemical reactions specific for hemoglobin.[13]

Both odontogenic and hematogenous origin

Sakamoto et al. demonstrated that RBs are amyloids that are formed due to unusual alteration of the epithelial differentiation, providing hair keratin and the other is hemorrhage to provide hemoglobin, thus concluding that both are required for the genesis of hyaline bodies.[14] However, they did not comment on the origin.

Neither odontogenic epithelium nor hematogenous origin

Ultrastructural studies by Jensen and Erickson did not support the odontogenic epithelial or hematogenous origin for RBs.[15]

STAINING PROPERTIES OF RUSHTON BODIES

RBs take up Gram-negative stain. They give positive reaction with various stains such as Prussian blue (pale to strong reaction), aldehyde fuschin (positive after oxidation with permanganate), combined aldehyde fuschin-alcian blue method (strong purple), TPA-amido black (light blue to black), Papanicolaou stain (orange G), Masson's trichrome (dark pink) [Figure 4], Weigert's elastin solution, orcein, modified Mallory's stain for keratin, rhodamine B, thioflavin T and Congo red. RBs stain negatively with Von Kossa's method for calcium and periodic acid–Schiff method for mucopolysaccharides.[16]

Figure 4

Dark pink-stained Rushton bodies showing characteristic hairpin-like structure stained with Masson's trichrome stain (×10)

IMMUNOHISTOCHEMICAL CHARACTERISTICS

They show positivity for hair keratin, keratin 17 and hemoglobin α-chain. They appear blackish brown and refractile on staining with CD44.[16]

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Conflicts of interest

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