Veterinary clinical pathology最新文献

A 5-year-old neutered female Beagle was presented with lethargy, vomiting, and reduced appetite. Physical examination revealed mild hyperthermia and a cutaneous thickness on the right thigh. Hematology showed marked leukocytosis and moderate thrombocytopenia, consisting of 80% of atypical circulating cells, initially suggesting acute undifferentiated leukemia. Two weeks later, repeated hematology revealed unremarkable results. Cytology of the skin lesion showed a round cell neoplasia with features similar to the atypical circulating cells. Following the development of multiple cutaneous nodules and recurrence of clinical signs, further diagnostics, including flow cytometry, histopathology, and immunohistochemistry (IHC) of the skin nodules, as well as PCR for antigen receptor rearrangement (PARR) and immunocytochemistry (ICC) from the initial blood smear, confirmed a neoplastic T-cell proliferation consistent with cutaneous T-cell lymphoma with a probable transient leukemic phase. Despite chemotherapy, remission was short-lived, and the patient relapsed, ultimately leading to euthanasia. This case highlights a rare instance of transient leukemia likely originating from a primary cutaneous T-cell lymphoma, emphasizing the need for comprehensive diagnostic workups, combining hematology, biochemistry, cytology, flow cytometry, and immunophenotyping to avoid misclassification in hematologic malignancies.

A 5-year-old spayed female golden retriever with a history of cutaneous asthenia (Ehlers-Danlos-like syndrome) was presented with a newly noted large hindlimb mass. Cytologic evaluation performed at the referring veterinarian was consistent with a keratinizing lesion. However, a second cytologic sample was obtained from the mass, aspirating from multiple aspects, and was concerning for a sarcoma. The mass was excised and submitted for histologic evaluation. The mass effect was diagnosed as a keratinizing cyst. Additionally, there were severe dermal collagen and elastin abnormalities with multifocal fibrosis and hemorrhage (consistent with cutaneous asthenia). To the best of the authors' knowledge, this is the first report of the cytologic findings in the skin of a canine with cutaneous asthenia.

An 8-year, 3-month-old female, entire Boxer dog presented to the Queen Mother Hospital for Animals (QMHA), Royal Veterinary College (RVC) for evaluation of increased upper airway noise and dysphagia. A laryngeal mass had been identified by the referring veterinarian 5 months previously while the dog was undergoing general anesthetic for removal of oral masses (confirmed as peripheral odontogenic fibromas). At this time, no clinical signs were associated with the mass. However, in the weeks prior to presentation, the dog became unable to tolerate solid food and started showing respiratory symptoms relating to the mass and was subsequently referred for evaluation. CT examination revealed a 35 × 28 × 39 mm soft tissue mass occupying the right side of the rima glottidis, displacing the laryngeal lumen. The mass extended from the level of the rostral margin of the tympanic bulla to the level of C1 and dorsally into the caudal aspect of the nasopharynx. Direct aspirate preparations (Figures 1 and 2) from the laryngeal mass were air-dried, fixed, and stained using modified Wright stain (Hema-tek 3000, Siemens).

Incisional biopsy samples obtained at the same time as the aspirates were fixed in formalin, routinely processed, and stained with H&E.

Sections had a densely cellular pleomorphic malignant neoplasm, composed of diffuse sheets of irregularly polygonal to elongate cells of two populations. The more prominent population had large amounts of vacuolated cytoplasm with lower numbers of smaller round cells with moderate amounts of finely granular eosinophilic cytoplasm. Most cells had a single irregularly round nucleus with one prominent large nucleolus. Anisocytosis and anisokaryosis of the larger cells were marked, with frequent multinucleated giant cells and 57 bizarre mitotic figures in 2.37 mm² (Figure 3). Atypia of the smaller cell population was mild. The histological interpretation was an atypical malignant neoplasm with differentials including rhabdomyoma/sarcoma, oncocytoma, granular cell tumor, amelanotic melanoma, or histiocytic sarcoma.

Histochemical staining revealed strong cytoplasmic positivity for periodic acid-Schiff (PAS) in the small cells but negativity in the larger cells, diffuse strong membranous, and cytoplasmic positivity for vimentin in approximately 95% of cells (Figure 4), diffuse moderate cytoplasmic positivity for desmin in approximately 80% of cells, and negativity for toluidine blue, phosphotungstic acid hematoxylin (PTAH), cytokeratin, ionized calcium-binding adaptor molecule 1 (Iba-1), melan-A, smooth muscle actin (α-sma), neuron-specific enolase (NSE), and S100 (Table 1).

Based on these staining characteristics and cellular pleomorphism, a diagnosis of rhabdomyosarcoma was made.

Laryngeal rhabdomyosarcoma is mainly reported in adult dogs, being locally invasive but rarely metastatic. This local invasion makes complete excision difficult, with tumor recurrence often resu