Schlumberger and Lucki — Tumors in Fishes 



687 



author suggested that the tumor represented a bomo- 

 logue of the pigmented mole in man. 



Hadoow and Blake, 1933: The authors report two 

 skin tumors in a thomback ray Raja clavata. Both 

 neoplasms were sessile and lobulated. The brger mea- 

 tared 4 z 2.1 cm., was distinctly paler than the normal 

 skin, but contained scattered deposits of melanin; the 

 smaller, measuring 2 x 1.5 z 0.5 cm., was heavily laden 

 with melanin. Histologically they were richly cdkilar, 

 composed of dense collections of melanobUsts poM Ci iing 

 extremely large nuclei. Each tumor was traversed by 

 coarse fibrous trabeculae and rifted with many thin- 

 walled blood sinuses. The melanin was present mainly 

 in the form of intracellular granules, though some was 

 found in the tissue spaces. 



Haussler, 1934: A second report by this author 

 about melanomas that occurred in hybrids of Xipko- 

 pkorus and PlatypoecUus. In the 5 cases presented the 

 tumors were found in the region of the tail and were 

 derived from macromelanophores. Whether the tumors 

 were benign or malignant was not established. 



NiGRELLi and Gordon, 1944: A melanotic tumor 

 was found in a silverside Memdia beryUina penhtsuUu. 

 The fish measured 4.7 cm. in length ; the tumor covered 

 an area of 5 z 1.5 z 1.0 mm. and extended along the 

 sides of the body. In the normal fish a broad band of 

 melanof^ores forms a syncytium in the region of the 

 lateral line; these may have been the cells of origin of 

 the tumor. Histologically, the pigment cell overgrowth 

 in this fish appeared to be quite like the melanotic 

 tumors reported in hybrid killifishes by Reed and Gor- 

 don. The tumor contained melanin-bearing cells of dif- 

 ferent sizes, corresponding somewhat to the variations 

 in size normally encountered The cells spread laterally 

 in the corium, though in some areas they penetrated the 

 epidermis as well as the underiying fascia, muscle, and 

 bone. 



ERYTHROPHOROMA 



Tumors arising from the red pigment containing 

 erythrophores (allophores) have been reported in a 

 trout, a flatfish, a tunnyfish, a gurnard, and in 

 hybrid killifish (Table 19). The most deUiled ac- 

 count is that of Smith (188) describing the lesions 

 in a flatfish Pseudopleuronectes americanus. A red 

 tumor, 3x2 cm., was situated on the pigmented 

 side 4 cm. behind the right operculum, where it in- 

 vaded the subjacent tissues to the depth of the ex- 

 traperitoneal muscles. Similar though smaller lesions 



were scattered over the body: 2 near the postater 

 margin of the main mass, and 2 oo the iioapis> 

 mented side. Visceral tumors were also present: 

 10 in the liver, 10 in the kidneys, and 3 in the 

 spleen where they nearly replaced the nonnal par- 

 enchyma. Microscopkrally maases of wfiniitt-ihKipied 

 cells supported by ddicate capillaries ettcndcri 

 throughout the thickened corium as far as the under- 

 lying muscle bundles. Frosen sections of fre^ tunwr 

 tissue showed small pigment granules, varying in 

 color from vermilion to orange, and iKcaent in many 

 of the celb. Smith regarded the large skin lesion as 

 the primary site of the tumor and the smaller 

 nodules as metastases. 



In 1929 Kosswig reported erythropboromas in 

 two male fish produced by back-crossing an F| red 

 finned bluck killifish hybrid to a pure line red-finned 

 platyfish. In subsequent experiments (104) he ob- 

 tained a similar lesion in an Fi hybrid of Xipko- 

 phorus montezuma and X. heUcrii. Kosswig inter- 

 preted the lesion as a dominant mutation in a soma- 

 tic cell. Only in a single Fi hybrid of X. heUem 

 and PlatypoecUus maculatus did typical erythro- 

 phoroma develop. When this hybrid was croased 

 with a pure line X. kellerii, erythropboromas were 

 found in 5 of the offspring. Gordon (59) has sug- 

 gested that the tumors described by Kossw^ may 

 rq>resent melanomas which were invaded by erjrthro- 

 phores, rather than true erythrofdioromas. 



Abatracta of oUmt reported csmb af Brytkrop h o r aii 



Takahashi, 1929: On the left side just behind the 

 head of a gurnard Chelidomchtkys kmmm wis a tnmor, 

 8.5 X 7 X 7 cm., which infiltrated the muscfes down to 

 the vertebrae and bulged into the coelom. On scctioo 

 it was greenish-brown and firm. The tumor cells in- 

 filtrated the surrounding tissue, and were o\^. with 

 large vesicukr nuclei and a scanty cytoplasm which in 

 some instances contained yeUowi^reen pigment granules. 

 By chemical methods the ceUs were identified as allo- 

 phores, a term accepted as synonymous with "etytluo- 

 phore." 



Thomas, 1931 b: A subperitoneal erythrophoroma 

 was found in a tunny fish GymmostriM tiktwwf. The 

 tumor was of the same siae and color as a aniD oraace. 

 lay at the level of the liver, and was covered 1^ peri- 



Speck* 

 Gurnard CktHdonUkthys kumu 

 Killifishes (PlatypoecUus maculatus (9) 



(Xiphcpkenu kelUrii 

 Tunny fish Gymnosarda aUtttrata 

 Trout fpcciet not given 

 Flatfish Pseudoplturonecitt americ. 

 Killifishes (P. maculatus 



{X. hdUrii 



