Search Results (4)

Compared to the number of studies on the neoplasms of laboratory rodents, fewer studies have focused on spontaneous neoplasms in pet rodents. Notably, the mouse mammary tumor virus (MMTV) is associated with mammary tumors in rodents. In this study, 77 tumors and tumor-like lesions of biopsy samples were collected from 70 pet rodents, including hamsters (n = 47), guinea pigs (n = 16), unknown species (n = 4), rats (n = 2), and a gerbil. Fifty tumors were collected from 47 hamsters, in which the most common tumors were mammary tumors (13/50), followed by fibrosarcoma (9/50), mast cell tumors (4/50), and squamous cell carcinoma (4/50). The collected subtypes of mammary tumors in hamsters included tubular carcinoma (n = 5), tubular adenoma (n = 4), carcinoma and malignant myoepithelioma (n = 1), simple tubular carcinoma (n = 1), adenosquamous carcinoma (n = 1), and tubulopapillary adenoma (n = 1). In addition, twenty tumors were collected from guinea pigs, in which the most common tumor was lipoma (6/20), followed by adenocarcinoma of the mammary gland (4/20), trichofolliculoma (2/20), and collagenous hamartomas (2/20). In guinea pigs, the subtypes of mammary gland tumors were tubular carcinoma (n = 2), tubular and solid carcinoma (n = 1), and tubulopapillary carcinoma (n = 1). In 20 cases of mammary tumors, MMTV was not detected, implicating no evidence of MMTV infection in mammary oncogenesis in pet rodents in Taiwan. Full article

Folliculosebaceous cystic hamartoma (FSCH) is an uncommon hamartoma that usually presents on the central face area of adults as an asymptomatic, solitary dome-shaped or pedunculated papule. We report a case of a 35-year-old female who presented with six-months history of skin lesions on her labia majora. Histological findings included cystically dilated hair follicles with branching epithelial strands and interconnecting sebaceous gland consistent with the diagnosis of FSCH. The genital variant of FSCH was first described in 1998 and since then only six cases have been reported in the literature. We aim to increase awareness of this rare presentation due to the significant psychological implications and the risk of misdiagnosis. Full article

Background: Panfolliculoma (PF) is a relative rare, benign follicular tumor comprised of all elements of the hair follicle, with a limited number of cases reported in the literature. Articles on the demographic and pathological analysis of this tumor are also lacking. Case presentation: In this report, we presented an unusual case of cystic PF on the back of a 14-year-old male, and we performed a thorough literature review and analysis of all previously reported cases. Conclusions: PF is a rare benign follicular neoplasm with characteristic differentiation toward all components of the hair follicle. In our analysis, PF occurred most frequently on the head region and was usually diagnosed in middle- to old-aged persons, with cystic PF being the most common histologic subtype. Since this tumor is rare and easily misdiagnosed as other tumors both clinically and pathologically, a thorough understanding of the histopathological manifestations and differential diagnosis of this tumor is necessary for both dermatologists and pathologists. Full article

Since small mammals are gaining popularity as pets in Poland, the number of tumour samples submitted for histopathological examination is quite high. This study was a retrospective analysis of cutaneous and subcutaneous tumours in small pet mammals submitted for histopathology in 2014–2021. The analysis included 256 tumours sampled from 103 guinea pigs, 53 rats, 43 pet rabbits, 21 ferrets, 17 hamsters, 8 degus, 5 African pygmy hedgehogs, 3 Mongolian gerbils and 3 chinchillas. Tumours were diagnosed based on routine histopathology, with additional immunohistochemistry when necessary. The results of this study revealed that the vast majority of cutaneous tumours in guinea pigs were benign, with a predominance of lipoma. Adnexal tumours constituted a significant percentage of cutaneous tumours in guinea pigs (24.3%, with the most common being trichofolliculoma), pet rabbits (46.5%, with the most common being trichoblastoma), ferrets (33.3%, mostly derived from sebaceous glands), hamsters (52.9%, with the most common being trichoepithelioma) and gerbils (66.7%, scent gland epithelioma). Soft tissue sarcomas were a predominant group of tumours in rats (52.8%, with the most common being fibrosarcoma), African pygmy hedgehogs (100%), degus (87.5%) and chinchillas (66.7%). Melanocytic tumours were only sporadically seen in small mammal pets. Mast cell tumours were diagnosed only in ferrets, while epitheliotropic T-cell lymphoma was diagnosed only in a hamster and a degu. In summary, malignant tumours constitute a significant percentage of cutaneous tumours in many species of small mammal pets. Therefore, each cutaneous tumour should be sampled for further cytologic or histopathologic diagnosis. Full article