University Museum of the State University "Gabriele d'Annunzio", Piazza Trento e Trieste, no. 1, 66100 Chieti, Italy.
Int J Paleopathol. 2022 Jun;37:6-8. doi: 10.1016/j.ijpp.2022.02.002. Epub 2022 Feb 26.
To describe a case of an expansive endocavitary lesion at the level of the caudal tract of the vertebral column of a juvenile fish (Pycnodont) from the Late Cretaceous (Cenomanian) of Lebanon (Hjoula).
The specimen is part of the Paleontological Collection of the University Museum of Chieti, Italy, Inventory Number P #23752.
The specimen was observed macroscopically, as well as under the stereo-microscope (Leica Wild M 8); aspersion with ethanol and razing light were used to improve the observations and to take micro-photos.
The fossil juvenile fish has a visibly altered macroscopic anatomical morphology at the level of the caudal part of the vertebral column, which is pathological in comparison with the normal anatomy of the Pycnodonts.
Although diagnosis cannot be certain, comparative analysis notes morphological and topographic affinity between the paleopathological case described here and notochordal chordoma, which affects some living fish.
This lesion represents the first case of a nonosseous tumor in a fossil fish, and suggests that this type of neoplasm was among the first of the neoplastic diseases to appear on Earth.
Diagnosis rendered from fossil remains is complex and is further limited by the rarity of the condition in the past.
Continued comparative analysis of bony changes noted in this specimen with other fossil and living fish will contribute to our understanding of disease in the Earth's earliest inhabitants.
描述一例来自黎巴嫩（Hjoula）晚白垩世（Cenomanian）的幼年鱼类（Pycnodont）椎管尾部腔内扩张性病变。
标本为意大利 Chieti 大学博物馆古生物学收藏的一部分，编号为 P #23752。
标本进行了宏观观察，以及使用立体显微镜（Leica Wild M 8）观察；使用乙醇喷雾和光蚀来改善观察并拍摄微照片。
与 Pycnodonts 的正常解剖结构相比，该幼年鱼类的脊柱尾部区域的骨骼宏观解剖形态发生了明显的病理性改变。
尽管不能确定诊断，但比较分析表明，这里描述的古病理学病例与影响一些活鱼的脊索瘤在形态和位置上具有亲缘关系。
该病变代表了化石鱼类中非骨源性肿瘤的首例病例，并表明这种类型的肿瘤是地球上最早出现的肿瘤疾病之一。
从化石标本做出的诊断很复杂，并且由于过去这种情况很少见，因此受到限制。
对该标本中观察到的骨骼变化与其他化石和活鱼进行持续的比较分析，将有助于我们了解地球最早居民的疾病。
