An unusual case of a mature teratoma on the left perineal region of a young cat: surgical treatment and pathological description

An unusual case of oropharyngeal mature teratoma in a kitten

Background

Extragonadal teratoma in the head and neck region is unusual in veterinary medicine. So far, only one case of oropharyngeal teratoma has been reported in a cat.

Case description

In this report, a 5-month-old kitten was brought to the clinic with the complaint of difficulty breathing, food intake, and oropharyngeal mass. In clinical examination, there was a large mass, protruding from the localization included left buccal mucosa, soft palate, and extending into the oropharynx but no cranial extension was observed in CT scans. The mass was completely resected. Macroscopically, the mass measured 4.5 × 6.5 cm2 and contained solid and cystic areas associated with soft and hard tissue components.

Findings/treatment and outcome

Histopathology revealed an extragonadal solid-cystic (grade 0) oropharyngeal mature teratoma containing structures from endoderm, mesoderm, and ectoderm. After an 8-month follow-up control period, no signs of recurrence were observed.

Conclusion

The case was deemed worthy of being presented with its clinical, radiological, and pathological findings, and complete resection was curative for mature teratoma.

Case report: Mature extragonadal teratoma at the proximal part of the tail in a kitten

An 8-month-old, intact male, domestic shorthair cat was referred for a mass on the proximal ventral part of the tail which had been found since the animal was born, and due to the presence of a linear fissure with rows of ectopic teeth, the veterinarian suspected that the mass had recently ruptured. Tail amputation was elected and the entire mass was successfully surgically excised. From the gross examination, this mass had an open cyst-like structure with a prominent area composed of hair, teeth, and bone. Histopathology revealed two components of germinal layers including hair follicles, adnexal tissue, neural tissue, teeth, muscle, fat, bone, and lymphatic vessels. The histopathological diagnosis was consistent to mature teratoma. Although, complete excision could not be definitively confirmed histologically, this kitten is currently well and has not developed any recurrent mass at the surgical site after 2 years of post-operation.

Diagnosis and surgical management of malignant ovarian teratoma in a green iguana (Iguana iguana)

Background

Ovarian tumors in reptiles are uncommonly reported in the literature and for green iguanas previously reported cases include teratomas, one adenocarcinoma and one papillary cystadenocarcinoma. The present report is the first of a malignant ovarian teratoma in a green iguana. Complete and detailed pathological features, differential diagnosis and surgical management of malignant ovarian teratoma are discussed in this paper.

Case Presentation

A 9-year-old intact female green iguana (Iguana iguana) with a clinical history of persistent anorexia and progressive abdominal distension was referred to the surgery department. On physical examination, a presumptive diagnosis of follicular stasis was established. Radiographic evaluation showed a large radioopaque mass within the abdomen, which was visible both in latero-lateral and ventro-dorsal exposures. Abdominal ultrasonography showed a large intra-abdominal mass, with numerous cyst-like structures filled with liquid and a heterogeneous aspect with hypoechoic areas. Exploratory laparatomy was thus suggested and the mass was removed surgically. The histologic findings of the neoplasm were consistent with those of ovarian malignant teratoma. Surgical excision of the mass in our case was considered curative and after a follow-up period of 6 months the animal has recovered completely.

Conclusions

A malignant ovarian teratoma has not been previously reported in green iguana and should be included in the list of differential diagnosis of ovarian tumors in this species. This report will contribute to a better understanding of the pathology of this rare tumor in green iguanas.

Feline coccygeal teratoma: immunohistochemical characterization of immature tissue components

Congenital teratomas arising in the coccygeal region have not been reported in domestic animals. This report describes a congenital coccygeal teratoma in a male Burmese cat. A round to oval expansile mass with solid and cystic areas was found ventral to the 5th to 7th caudal vertebrae. Microscopically, the tumour was composed of derivatives of all three primordial germ layers with neuroectodermal predominance. Immunohistochemical double labelling identified immature tissue components in combination with Sox2, a regulator of stem cell proliferation and differentiation. Few Sox2-positive cells co-expressed the neural crest stem cell markers vimentin and neurotrophin receptor p75(NTR). Not all Sox2- and p75(NTR)-positive cells expressed vimentin. An overlapping expression of vimentin-negative and Sox2-, p75(NTR)-positive cells and GFAP- and p75(NTR)-positive cells may indicate a transition stage from immature to mature non-myelinating Schwann cells. Periaxin-positive myelinating Schwann cells surrounding neurofilament-positive axons were observed. Sox2 was additionally expressed in immature odontogenic epithelial cells and in immature cells of endodermal origin. Sox2 was not observed in mature cells, with the exception of satellite glial cells and mucous glands. Despite the presence of immature tissue components, no recurrence was observed 1 year after surgical removal.