Schlumberger and Lucki — Tumors in Fishes 



683 



inner surface of the operculum of a gurnard Tri^ 

 ImeaUi. Histologically it consisted of a mass of dilated 

 capillaries. 



Johnstone, 1915: The pupU of the left eye of a 

 stickleback Punptms Imm^tms was surrounded by a 

 brown, raised, nodular swelling. The cornea was mot- 

 tled Mf-ith opaque specks, while small arborescent growths 

 arose from its center. On section the tumor, consisting 

 of a plexus of proliferating ca{Hllaries, occiipied the 

 subcutaneous subconjunctival and iridial tissues. The 

 papillae noted on the cornea were masses of epithelial 

 cells. 



Johnstone, 1924: In the body wall of a mackerel 

 Scomber scombrus was a soft, red tumor, 5 x 1.5 cm., 

 that infiltrated the adjacent musculature. It was com- 

 posed of dilated capillaries supported by proliferating 

 connective tissue. 



Johnstone, 1925: In the swim bladder of a codfish 

 was a tumor that apparently arose from the plexus of 

 vessels normally present in this region. It consisted of 

 numerous dilated vessels supported by a loose connective 

 tissue stroma infiltrated by collections of l>'mphoid 

 tissue. 



JoHNSTO.VE, 1925: A firm mass, 2x4 inches, was 

 found in the trunk musculature of a ling Molva molva. 

 A central dark area was interpreted by the author as 

 clotted blood; the periphery consisted of many dilated 

 vessels, capillaries, and proliferating angioblasts. 



Johnstone, 1925: The author reports single lesions, 

 averaging from 2 to 3 cm. in diameter, that arose in 

 the tnmk musculature of 3 plaice Pleuronectes f^atessa. 

 Histologically they were made up entirely of thin-walled 

 vessels that infiltrated the surroimding tissue. 



Johnstone, 1926: Many hard nodules, ^ to 1 inch 

 in diameter, were palpated throughout the trunk muscu- 

 lature of a codfish Polhchius virens. Histologically 

 each nodule consisted of a mass of blood vessels and 

 accompanying connective tissue stroma. 



Johnstone, 1926: The last 3 inches of the rectum 

 of a hake Merlucdus merluccius was swollen, deep red 

 in color, and resembled a huge blood clot. On section 

 the mucosa and submucosa were almost replaced by 

 dilated vascular spaces, many of which contained ac- 

 tively proliferating angioblasts. 



LYMPHOSARCOMA 



A discussion of lymphosarconia in fishes must be 

 introduced by pointing out that circumscribed col- 

 lections of lymphoid tissue in the form of nodes, do 



not occur in these animals. They are found in the 

 phylogenetic scale only in some birds (aquatic) and 

 in all mammab (93). In elasmobranch fishes, hema- 

 topoiesis takes place in the spleen, the mesooephros, 

 the submoooaa of the intestine, and the subcapsular 

 tissue of the gonads. In teleosU the mesooephros is 

 generally the dominant hematopoietic organ; the 

 ^leen and submucosa of the intestine have only an 

 accessory role. This dbtribution of the hematopoie- 

 tic tissue accounts for the frequent location <rf lym- 

 phosarcoma in the kidney; U., in 15 of the 20 re- 

 ported cases (Table 17). 



In the older reports lymphosarcoma has not al- 

 ways been separated from other forms of sarcoma; it 

 is probable that several of the tunaors which in this 

 review are included in the latter grot^ are b fact 

 lymphosarcomas. 



Plehn (162) observed that the kidney of a gold- 

 fish Carasmts aurattu was increased to 20 times its 

 normal size. The organ was firm and white; the 

 normal renal tissue had been almost wholly replaced 

 by lymphoid elements. Metastases were found in 

 the liver. The author believes that renal insuffi- 

 ciency accounted for the generalized edema that 

 was present. In a herring Clupea harengms, measur- 

 ing 30 cm. in length, Johnstone (91) found an 

 intracoelomic tumor, 5 x 2.5 cm. Histologically it 

 was composed of connective tissue stroma padtaed 

 with lymphoid cells. It is probaUe that the si^ 

 capsular tissue of the gonads was the primary site 

 of the neoplasm. Recently, Nigrdli (142) has re- 

 ported several interesting cases of metastasixing 

 lymphosarcomas. Twelve fully grown pike Esox 

 lucius, kept In oat tank, succumbed at various inter- 

 vals at tl^ N. Y. Aquarium during the years 1940 

 and 1941. Both sexes were represented. There were 

 no external manifestations of disease, but autopsies 

 showed comparatively massive growths in the kid- 

 neys, with metastasis to the spleen and liver. His- 

 tologkally the tumors were identified as lymphosar- 

 comas composed mainly of large lymphoblasts sup- 

 ported by irregular strands of fibrous stroma and a 

 delicate reticulum. 



Another metastaiifing tunKw was found in a male 



Ta»u IT: LTi(V«a«A«eniu 



