7^ 



Cancer Research 



have been prinnary. The presence of the larj^c multi- 

 nucleated cells suggests that it may have been a 

 rhabdomyoma. 



One of us (116) has studied the multiple large 

 papillomas of the skin and eyes in the edible green 

 turtle Ckelonia mydas. Three ^jccimens, caught off 

 Cape Sable, were available for examination. The 

 tumors were located on the tail, flippers (Fig. 52), 

 the axillae, neck, eyelids, corneas. In one instance 

 bilateral corneal growths had produced blindness 

 (Fig. 51). The tumors were hemispherical and had 

 a roi^ warty surface which was ulcerated in some 

 areas. They were sessile or had a broad peduncu- 

 lated base, and ranged in size from small warts a 

 few millimeters in diameter to masses 20 cm. in 

 width. The tumors were rubbery in consistency and 

 on section were white and bloodless. Histologically 

 they were papillomas, with arborescent connective 

 tissue papillae covered by several layers of keratiniz- 

 ing squamous epithelium (Figs. 53, 54). 



The connective tissue component became more 

 prominent as the tumor increased in size, and its 

 cellularity gave evidence of active proliferation. 

 Although this never yielded the picture associated 

 with malignant connective tissue tumors, numerous 

 spherical masses, from 3 to 5 cm., were found in the 

 lungs of one of the turtles (Fig. 57). These were 

 oooqposed of dense fibrous tissue covered by ciliated 

 columnar re^iratory epithelium (Figs. 58, 59). 

 Whether they were primary tumors of the lung or 

 idiether they represented a metastatic dissemination 

 of the neoplastic connective tissue of the skin papil- 

 lomas cannot be determined with certainty, but an 

 origin m sUu appears most probable. In this con- 

 nection may be mentioned the brief note of Tsvetae- 

 va (219) reporting a fibroadenoma of the lung in a 

 Turkestan turtle, Testudo horsjeldi. Whether the 

 animal bore any skin papillomas was not stated. 

 Since many papillomas (warts) of man and other 

 aninwls are of proved virus etiology, it is interesting 

 to consider a similar etiology for these tumors of 

 turtles. 



Smith and Coates (191, 192) observed similar 

 fibroepilhelial growths in six specimens of Ckelonia 

 mydcs. Besidd the more common papillary struc- 

 tures, they also noted occasional smooth elevations 

 which CO lectioo nere composed of interlacing bands 

 of connective tissue varying in density and covered 

 by a slightly thickened epithelium. The investigators 

 regarded these as fibromas. At times both types of 

 growth coexisted. In a subsequent {xiper (192) the 

 authors reported that in more than half of 250 tu- 

 mon occurring in the six turtles examined they 

 found ova of the parasitic trematode Hapdotrema 



i oust rii turn (later [193 J reclassified as Distomum 

 constrictum) . The authors believe that the ova 

 were probably dep>osited in the preexisting vascular 

 tumor tissue by the migrating flukes, and remained 

 there without affecting the subsequent growth of the 

 tumor. They concluded that the ova were not of 

 primary importance in the etiology of the neoplasm. 



Recently, however, Nigrelli (142) reported find- 

 ing as many as SO leeches, Ozobranchus branchiatus, 

 in various stages of growth on a bit of the papilloma 

 only Yi inch square. The largest leeches measured 

 10 mm. in length, 5 mm. in width; all were strongly 

 contracted. In the regions where the leeches were at- 

 tached, the vascularity of the tumors was increased. 

 The hirudin secreted by the leeches may have a 

 direct stimulating effect on the growth of the tumor, 

 or may affect it indirectly by improving the circula- 

 tion. The author suggested further that the leeches 

 may act as vectors for viruses or other parasites 

 that may be causative in the development of the 

 papillomas. 



In these turtles Smith, Coates, and Nigrelli (193) 

 observed a papillomatous disease of the gall bladder 

 associated with the presence in that organ of the 

 trematode Rhytidodoides similis. Occasionally the 

 tumors formed discrete patches which surrounded 

 and occluded the orifice of the cystic duct. Not in- 

 frequently the entire mucosa was thickened and 

 rugose, the wall edematous and infiltrated with 

 lymphoid elements. These changes were accompa- 

 nied by capillary dilatation and connective tissue 

 proliferation. The mucosal glands were dilated and 

 tortuous but in none of the 100 affected gall blad- 

 ders examined was there any evidence of malignant 

 change. Although most of the worms lay free in the 

 bile of the gall bladder, some were found attached 

 to the papillomatous portions of the mucosa. The 

 authors believe that the growths are the result of 

 mechanical or chemical factors associated with the 

 presence of the parasite. 



Two musk turtles Stemotkaerus odoraius bearing 

 skin papillomas were obtained by us from the Phila- 

 delphia Zoological Gardens. In one there was a 

 growth, 5x5x8 mm., on the dorsum of the tail 

 (Fig. 55) and another on the right front flipper. 

 In the second animal a single tumor, 4x5x5 mm., 

 was present on the left hind flipper. The three small 

 tumors were very firm in consistency and deeply 

 lobulated. On section they closely resembled the 

 common warts of man. A loose, well vascularized 

 connective tissue core was covered by multilayered 

 stratified squamous epithelium showing hyperkera- 

 tosis and parakeratosis (Fig. 56). Long pegs of epi- 

 thelial celb extended deeply into the underlying 



