Schlumberger and Lucki — Tumors in Fishes 



677 



Specie* 



Crucian carp Carassius earasiius (3) 



Barbel Barbms fiuviatiolis 



Sea pike EJops saurus 



Minnow Phoxinus 



Dogfish Squalus mitsukurii 



Codfish PoUackius virens 



Cat shark ScyUiorkintu canUtda 



Jewel fish Hemichromis bimactdatus 



Tabu 10: Cbowdsoha 



SkttO bones 



Maodible 



Sttbcataneous 



Mandible 



Lumbar vertebrae 



Pre-orbital 



Skin 



Operculum 



Antkor 



Mubow. 1915 

 Satteck.1917 

 Sorbeck. 1921 

 Andxi. 1927 

 TakAhashi. 1929 

 Thonaa, 1932d 

 Thomas, 1933b 

 NigrcUi ft Gordon, 1946 



carassius. The tumors were massive and nearly filled 

 the cranial cavity. These cases were cited by Thomas 

 (1932 b) and illustrated by Plehn, 1924. 



SuRBECK, 1917: In a very lean barbel Barbus jtuvia- 

 tiaJis a tumor was found in the posterior region of the 

 mandible. Approximately 1.5 cm. in diameter, it was 

 formed by the apposition of 2 spherical masses. The 

 skin over the anterior nodule was ulcerated, the ma^ 

 was ossified. The posterior nodule was composed en- 

 tirely of cartilage. 



SuRBECK, 1921 : A sea pike Elops saurus, 100 cm. in 

 length, bore a pedunculated tumor the sire of 2 fists on 

 its ventral surface behind the pectoral fins. It con- 

 sisted of dense plaques of fibrous tissue and cartilage. 



Andre, 1927: A minnow Phoxinus had a peduncu- 

 lated mulberry-like mass attached to the tip of the 

 mandible. The overlying skin was deeply pigmented, 

 the head was pulled down by the weight of the tumor. 

 Histologically, the tumor consisted of hyaline cartilage. 



Takahashi, 1929: A tumor, 10 x 7 x 5 cm., arose in 

 the region of the third to sixth lumbar vertebrae of a 

 dogfish Squalus mitsukurii. The overlying skin was ul- 

 cerated. The tumor, which consisted of hyaline carti- 

 lage, was fused with the third lumbar vertebra and 

 showed a central area of liquefaction necrosis the size of 

 a walnut. 



Thomas, 1932 d: Two symmetrical pre-orbital tu- 

 mors, each measuring 1.5 x 3 cm., were found b a 6 

 year old codfish PolUuhius virens. Covered by intact 

 skin, they were broadly sessile upon the lachrjinal bones, 

 but were separated from them and adjacent tissues by a 

 fibrous capsule. The tumors were very firm, partly 

 calcified, and consisted of typical cartilage cells em- 

 bedded in a fibrous matrix. 



Thomas, 1933 b: On the right flank below the pec- 

 toral fin of a cat shark Scylliorhinus canicula was a 

 tumor, the surface of which was partly denuded. It 

 arose from the connective tissue of the corium and 

 possessed a peripheral zone of hyaline cartilage; the 

 central portion was caldfied. 



NiGRELLi and Gordon, 1946: When first observed the 

 tumor appeared as a small swelling at the anterior 

 margin of the right operculum of a jewel fish Htmi- 

 chramis bimaculatus. Within two months it had attained 

 a size of 13 X 6 X 4 mm. The total length of the fiih was 

 52 mm. Histologically the tumor proved to be an osteo- 

 chondroma consisting chiefly of hyaline cartilage ar- 

 ranged in a more or less irregular pattern. The ftdi wm 

 the only pathologic specimen in about a hundred of the 



same species and strain that were kepi in a 150 giUoo 

 aquarium. 



OSTEOMA 



Osteomas are tumors frequently observed in 15 

 species of fishes (Table 11). The multiple osteomas 

 in a butterfly fish reported by William BeU in 1793 

 b probably the first recorded account of neo(dasm 

 in a fish. The tumors in this case were the size of 

 hazel-nuts and involved several haemal and neural 

 spines. Since similar lesions were found in several 

 ^>ecimens, the fish were classified as a separate spe- 

 cies; viz.fChaetodon arthriticus. The timior-bearing 

 fish are, however, now grouped with the normal 

 members of the species Piatax pinnatus. 



Several Japanese investigators (96, 175, 199) 

 have described localized bony overgrowths on the 

 ventral spinous processes (haemal spines) of the 

 sixth to eighth caudal vertebrae of the red tai, Pag- 

 rosomus major. The largest series, consisting of 102 

 fish, was reported by Takahashi (199). The growths 

 varied from the size of a pea to that of a large bean; 

 rarely were they as large as a walnut. In 28 cases 

 the tumor was single, in 64 there were 2 tumors; in 

 17, 3; and in 10, 4 or more. A line of fracture was 

 visible in several of the very small ttmK>rs. Taka- 

 hashi concludes that ossification of excess callus b 

 the initial step in the formation of these tumors. 



Three specimens of Pagrosomus major were cho- 

 sen by us at random from the collection at the Na- 

 tional Museum in Washington, and one bore tumors 

 identical with those descntied by Takahadii (Ftg. 

 25). Careful inspection of the roentgenograma (Fig. 

 26) and histologic sections failed to reveal oonvinc- 

 ing evidence of previous fracture. Tl^ cortex, wiiich 

 is very thin in the normal spinous process, was 

 greatly thickened (Fig. 27). As the growths in- 

 creased in size the cancellous bone became more 

 prominent until only a thin cortical layer <rf 

 bone remained (Fig. 28). The marrow ipacM 

 filled with well vascularized adipoae time; hma* 

 topoiesis does not occur in the booe marrow of 

 fishes, hence its absence in the fl a tiwmai OMikl be 

 anticipated* 



