Schlumberger and Lucki — Tumors in Fishes 



681 



in fishes (Table 14) are not convincingly neoplastic 

 in character. In the three instances involving the 

 stomach the lesions were diffuse and more suggestive 

 of hyperplasia than of true tumor; one was asso- 

 ciated with a parasitic infestation of the pyloric 

 ai^ndages. Plehn (157) reported a leiomyoma in 

 a shiner Albumus lucidus that arose in the trunk 

 musculature, was infiltrated by lymphocytes, and 

 contained minute hemorrhages. If the diagnosb of 

 leiomyoma was correct, the tumor probably had its 

 origin in the smooth muscle of blood vessels. 



Abstracta of reported cases of Ldomyoaia 



Plehn, 1906: On the ventral surface near the cardiac 

 end of the stomach of an 8 or 9 year old rainbow trout 

 Salmo goirdnem was a bean-sized mass. The overlying 

 mucosa was intact Histologically the cells were identi- 

 cal with the normal musculature of the intestine; only 

 the irregular arrangement was abnormal. No mitoses or 

 inflammatory cell infiltrates were present 



Plehn, 1906: In the trunk musculature of a shiner 

 Albumus lucidus between 1 and 2 years old, was a firm 

 hemispherical tumor 1 cm. wide. Histologically it con- 

 sisted of interlacing bundles of smooth muscle containing 

 small "round cell" infiltrates and minute hemorrhages. 

 Bffltoses were uncommon. 



Pesce, 1907: The stomach wall near the pylorus of 

 a trout Sdmo c<trpio was greatly thickened. The pyloric 

 af^ndages were filled with cestodes. Histologically the 

 cellular detaM and organization differed greatly from 

 what is regarded as normal in this region. The irregubr 

 fasciculi embedded in loose connective tissue meshes 

 were diagnosed as fibroleiomyoma. 



Thomlas, 1933 c: In a male, 3 year old herring 

 Clupea karengus, 18 cm. long, the pyloric segment of the 

 anterior gastric pouch was markedly hypertrophied. It 

 formed a cone-shaped, white mass that was covered by 

 peritoneum. The lumen of the stomach was normal. 

 Histologically the mucosa and serosa were intact, the 

 wall from two to three times its normal thickness. 

 Oblique, regularly arranged connective tissue trabeculae 

 formed partitions in the mass which consisted chiefly 

 of smooth muscle fibers. There was no evidence of m- 

 vasion of the surrounding structures. 



RHABDOMYOMA 



Rhabdomyoma has been reported in 8 species 

 (Table IS). The record of twice as many tumors 

 of striated mu-scle as of smooth muscle is probably 

 due to the common location of rhaMomyoma in the 

 trunk musculature where they are more readily ob- 



served. Histologically the tumors closely resemble 

 similar tumors found in man. Noteworthy is the 

 report by Yoimg (235) of a rhabdomyoma in each 

 of two turbot. The fishes had been sent from Eng- 

 land to New Zealand and kept there for ten years 

 in separate tanks. Tumors measuring Sy^ by ly^ 

 inches developed in both turbot at approximately 

 the same time and in the same location oo the non- 

 pigmented side of the body. The neoplasms were 

 soft and yellow, and histologically consisted of large 

 striated muscle fibers, many of which were edema- 

 tous and had partly disintegrated. 



The only rhabdomyoma that did not arise in the 

 trunk musculature was reported by Fiebiger (48). 

 It was foimd in the viscera of a codfish PoUackius 

 virens and measured 12x9x6 cm. The tumor was 

 encapsulated and could easily be separated from 

 the surrounding organs. Small cysts and groups of 

 celb that resembled hepatic celb were present among 

 the striated muscle bundles. This suggests that the 

 growth may have been primarily a teratoid tumor 

 in which the muscle fibers formed the predominant 

 element. 



Abstracts of other reported cases of Rhsbdonyons 



Adami, 1908: A red trout Salmo cJarkH bore a 3 cm., 

 spherical tumor on its left side 4 cm. behind the dorsal 

 fin. It was embedded in the musculature and projected 

 1.5 cm. above the general body surface. The tumor was 

 well circtmiscribed and separated readily from the sur- 

 rounding tissue. Histologically it was composed almost 

 wholly of multinucleate giant ceUs. Several of these 

 were of great length and resembled regenerating muscle. 

 In not a few, the part of the cell farthest from the 

 grouped nuclei showed definite striations. 



Bergman, 1921 : On the right side of a stint Osmtrus 

 cperUmus, directly behind the head, was a tumor, l.S x 

 1 z 1.2 cm. The gray-white mass had the consistency 

 of normal muscle and extended to the vertebral column. 

 Histologically it was well circumscribed by a thin fibril- 

 lar capsule. The parench>'mal celb were transwrscly 

 striated muscle fibers and myeloblasts in various stagr^ 

 of development. 



KoLMEB, 1928: A tumor was present in the trunk 

 musctilature of an adult tench TInm tmca. The o>'er- 

 lying scales in this region were approximatdy twice 

 normal size. Microscopically the tissue coosbted of 

 irregulariy arranged striated muscle fibers that formed 

 a tyfMcal rhabdomyoma 



Laorevt, 1930: Near the posterior border of the 

 right pectoral fin of a wraate Labnu mixtms was a pea- 



Sptck* 

 Rainbow trout Saima gairdnerii 

 Shiner Albumus lucidus 

 Trout Salmo carpio 

 Herring Clupta hartngus 



Tamm H: LnowTOMA 



Siu 

 Stomach waO 

 Trunk tnuKle 

 Stomach wall 

 Wall of ttomach 



Aalkor 

 Ptchn. 1906 

 Ptebn, 1906 

 P«Ke. 1907 

 Tikoaaa, 193Jc 



