Pituitary Adenoma in a Dumeril’s Ground , dumerili Zoltan S. Gyimesi1, DVM, Michael M. Gamer2, DVM, DACVP

1. Louisville Zoological Garden, 1100 Trevilian Way, Louisville, Kentucky 40213, USA

2. Northwest ZooPath, 654 W. Main St., Monroe, Washington 98272, USA

A b s t r a c t : A pituitary adenoma was diagnosed via histopathologic examination in an aged female DumeriPs ground boa, . The exhibited postural abnormalities, dull mentation, and poor mus­ Downloaded from http://meridian.allenpress.com/jhms/article-pdf/17/1/16/2208224/1529-9651_17_1_16.pdf by guest on 29 September 2021 cle tone prior to death. Pituitary neoplasms appear to occur very rarely in , but may be underreported if the pituitary gland is not routinely examined. This report illustrates the importance of submitting the brain or entire head for microscopic evaluation.

K e y w o r d s : Dumeril’s ground boa, Acrantophis dumerili, pituitary adenoma, endocrine, neoplasia

C ase R eport elongated cells that had variably placed small vesicular, mild­ ly anisokaryotic nuclei and single small nucleoli (Figure 4). An adult (greater than 20 year old), 13 kg, female Dumeril’s No mitoses were observed. The cells had abundant cytoplasm ground boa, Acrantophis dumerili, presented with unilateral filled with basophilic or amphophilic granules. Cellular for­ bullous spectaculopathy in July 2004. At the time of presenta­ mations were sometimes separated by delicate fibrovascular tion, keeper staff reported no other abnormalities with the stroma. A few areas of small follicle formation were noted snake. It was noted that it had been recently observed lying within the tumor, and the follicular lumina contained pro! on its back, a behavior herpetologic staff interpreted as a sign teinaceous material. Mild reactive bone formation was noted of being gravid. The snake was scheduled for anesthesia for in the calvarium adjacent to the neoplasm (Figure 2), The eth­ surgical treatment of the ocular problem two months after ini­ ology of the presenting ophthalmologic condition was tial presentation. On the morning of surgery, the snake undetermined. exhibited a dull mentation, and had poor muscle tone and decreased vigor. Anesthesia was induced and maintained with D iscussion 2 — 5% sevoflurane (SevoFlo®, Abbott Laboratories, North Chicago, IL). Wedge resection of the bullous spectacle and The morphologic features of this neoplasm, including the retrograde flushing of the affected lacrimal duct were per­ well-differentiated cell morphology, dense cytoplasmic gram; formed. The snake died during anesthetic recovery. ularity, follicle formation and perivascular palisades, are: A necropsy was performed on-site at the Louisville Zoo’s typical of the pituitary tumors arising from the pars interme- Health Center. Notable gross findings were moderate fat stores, multifocal accumulations of mucoid exudate in the lung/air sac lumen, multifocal tan-white masses in the wall of the lung, several encapsulated soft tissue nodules in the pan­ creas, and active ovaries containing follicles in varying stages of development. Some of the ovarian follicles were small, firm, and darkly pigmented. Escherichia coli and a Penicillium spp. were cultured from the lung lumen. Representative tissues including the entire head were pre­ served in 10% neutral buffered formalin. Histopathologic examination revealed bacterial bronchop­ neumonia, multiple pancreatic adenomas, glomerular thrombosis and marked sclerosis, and ovarian follicular degeneration and granulomatous oophoritis. Transverse sec­ tioning of the decalcified head revealed a roughly spherical 1.5 cm soft tissue mass replacing the pituitary gland and com­ pressing adjacent brain (Figure 1). Histologically, the mass represented a well-differentiated pituitary adenoma arising from and replacing the pars intermedia and expanding into the pars nervosa, but was demarcated from the pars distalis Figure 1. Transverse section through skull, Dumeril’s ground (Figures 2 and 3). The neoplasm was comprised of compact boa, Acrantophis dumerili. Note mass (t) on floor of calvarium chords, perivascular palisades, and small sheets of round to associated with dorsal displacement of brain (b). Bar = 1.5 cm.

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Figure 4. Pituitary adenoma, Dumeril’s ground boa, Acrantophis Figure 2. Transverse section through skull, Dumeril’s ground dumerili. Note cord-like formations (arrows) and sheets of neo­ boa, Acrantophis dumerili. Note tumor (t) that replaces the plastic round to elongated cells with abundant cytoplasm that entire pars intermedia. The tumor is demarcated from the pars closely resemble normal pituitary gland cells. Note palisading distalis (d), and infiltrates the pars nervosa (n). Also note flat­ cells (arrowheads) oriented around a blood vessel (v). H&E, bar tening of the ventral surface of the brain (b) due to tumor = 120 pm. Inset: Note dense cytoplasmic granularity in the neo­ compression. Note mild reactive bone formation (arrow) in plastic cells. H&E, bar = 35 pm. the floor of the calvarium (c). The clear zones in the image are artifacts of slide preparation. H&E, bar = 3.5 mm.

Washington University Medical Center identified a single case of a pituitary neoplasm in a snake (Linn, et al, 1996). More commonly reported endocrine tumors in reptiles involve the pancreas, adrenal gland, thyroid gland, and metastatic endocrine tumors of undetermined origin (Gamer, et al, 2004). Pituitary neoplasms in reptiles apparently are very rare, but could be underreported if the pituitary gland is not routinely examined. Pituitary adenomas occur most frequently in dogs (Duesberg, et al, 1995), horses (Schott, 2003), budgerigars (Bauck, 1987), and rats (Greenacre, 2004), and are consid­ ered rare in most other . Although morphologically benign, they can cause both mechanical and hormonal distur­ bances. Pituitary adenomas are typically slowly expansive and mechanical disturbances occur when the space-occupying effects lead to compression atrophy of adjacent portions of the pituitary gland and overlying brain. Hormonal distur­ bances result when hyper- or hyposecretion occur. These tumors have potential to alter secretion of any of the hor­ mones produced by the anterior and posterior lobes of the Figure 3. Pituitary gland, DumeriFs ground boa, Acrantophis pituitary gland including thyroid stimulating hormone (TSH), dumerili. Note thin capsular demarcation (arrows) between adrenocorticotropic hormone (ACTH), and growth hormone tumor (t) and pars distalis (d). H&E, bar = 400 pm. (GH). The most common functional pituitary adenomas in dogs and horses are ACTH-secreting macroadenomas leading dia of mammals, particularly those of horses. Although the to hyperadrenocorticism (Duesberg, et al, 1995, Schott, tumor invaded the pars nervosa, regional invasion of the pitu­ 2003). Whether the adenoma in this snake was functional was itary, or even into the floor of the pons, does not necessarily undetermined. Unfortunately, further special staining, constitute criteria for malignancy (Capen, 2002). Because this immunohistochemistry, and electron microscopy to better tumor was well-differentiated, with no anaplasia and minimal characterize the tinctorial and morphologic properties of the invasive features, it was considered benign. neoplasm could not be performed due to loss of the paraffin To our knowledge, this is only the second report of a pitu­ block containing the lesion during shipping. itary tumor in a . A review of the literature including The snake in this report exhibited non-specific clinical several comprehensive retrospective studies on reptile neo­ signs and the dull mentation and poor muscle tone were only plasia (Ramsay, et al, 1996, Gamer, et al, 2004, Sykes and noted the day of death. The observation of seeing this snake Trupkiewicz, 2006) along with searching the Registry of on its back is interesting, as this postural abnormality was Tumors in Lower maintained at the George likely an indication of central nervous system disease.

Volume 17, No. 1, 2007 Journal of Herpetological Medicine and Surgery 17 Although gravid boids have been reported to lay in unusual R eferences positions behaviorally (Ross and Marzec, 1990), it is unlikely this was the cause in this snake. It is more likely that the large Bauck L. 1987. Pituitary neoplastic disease in 9 budgies. Proc macroadenoma in this report was compressing the brain and AAV, 87-89. led to mass effect symptoms in this nongravid snake. We do Capen CC. 2002. Tumors of the endocrine glands. In Meuten DJ not believe that the pituitary adenoma was related to the uni­ (ed): Tumors in Domestic Animals, 4th Ed. Iowa State lateral bullous spectaculopathy noted in this snake University Press, Ames, IA:616-620. ante-mortem. Duesberg CA, Bertoy EH, Feldman EC. 1995. Diagnosis and This case illustrates the value of performing a complete treatment of macrotumors in dogs with pituitary-dependent necropsy including evaluation of the brain and pituitary hyperadrenocorticism. In Bonagura JD (ed): Kirk’s Current gland. In reptiles, amphibians, fish, and small birds and mam­ Veterinary Therapy XII, Small Animal Practice. WB Saunders mals, it is not uncommon to fix the entire head in formalin. Co, Philadelphia, PA:351-355. This form of submission is acceptable provided there is an Gamer MM, Hernandez-Divers SM, Raymond JT. 2004. Reptile appropriate ratio of formalin to tissue. In many cases, this neoplasia: a retrospective study of case submissions to a spe­

technique is the best method to preserve both normal struc­ cialty diagnostic service. Vet Clin Exot Anim, 7(3):653-671. Downloaded from http://meridian.allenpress.com/jhms/article-pdf/17/1/16/2208224/1529-9651_17_1_16.pdf by guest on 29 September 2021 tures and lesions within the head. Greenacre CB. 2004. Spontaneous tumors of small mammals. Vet Clin Exot Anim, 7(3):627-651. A cknowledgements Linn MJ, McNamara T, Steinberg JJ, Kress Y. 1996. Pituitary adenoma in a black-headed python (Aspidites We thank Elizabeth Hayden for technical assistance and Bill melanocephalus). Proc AAZV, 449. McMahan, Will Bird, and the rest of the herpetologic staff at Ramsay EC, Munson L, Lowenstine L, Fowler ME. 1996. A ret­ the Louisville Zoo for their assistance and support. rospective study of neoplasia in a collection of captive . J Zoo Wild Med, 27(l):28-34. Ross RA, Marzec G. 1990. Reproductive husbandry. In The Reproductive Husbandry of Pythons and Boas. Institute for Herpetological Research, Stanford, CA:39-74. Schott HC. 2003. Pituitary pars intermedia dysfunction: Equine Cushing’s disease. In Robinson NE (ed): Current Therapy in Equine Medicine 5. Saunders, Philadelphia, PA:807-811. Sykes IV JM, Trupkiewicz JG. 2006. Reptile neoplasia at the Philadelphia Zoological Garden, 1901-2b02. J Zoo Wildl Med, 37(1): 11-19.

Journal of Hornotnlooical Medicine and Sun?erv Volume 17, No. 1,2007