Multiple cutaneous plasmacytosis with multilobated (clover-leaf shaped) nuclei cells in a dog

Non Epitheliotropic B-Cell Lymphoma with Plasmablastic Differentiation vs. Cutaneous Plasmacytosis in a 12-Years-Old Beagle: Case Presentation and Clinical Review

Cutaneous lymphoid neoplasms and cutaneous plasmacytosis are rare in the dog; in human and in veterinary medicine, these have many clinical, cytological, histological, and phenotypic similarities, and a diagnosis of certainty is not easy. The aim of this study is to describe a case of cutaneous non epitheliotropic B-cell lymphoma (CNEBL) with plasmablastic differentiation vs. multiple cutaneous plasmacytosis (CP) in a dog, since the scarce bibliographic data on these topics. A 12-year-old male Beagle dog was presented for multiple, nodular, cutaneous, and subcutaneous, indolent masses disseminated on the whole body. Cytological, histological, flow cytometric, and immunohistochemical examinations, as well as complete radiographic evaluation, echocardiography, and abdominal ultrasound were performed. Cytology, histopathology, flow cytometric, and immunohistochemical examination, performed on the skin lesions, revealed a B-cell phenotype with plasmablastic differentiation. Nevertheless, a final diagnosis could not be achieved and it was categorized as a case of borderline CNEBL with plasmablastic differentiation versus CP. The dog was treated with a COP chemotherapeutic protocol. Total remission was obtained and relapse occurred 120 days later. To our knowledge, specific markers are actually unavailable to certainly differentiate CNEBL and CP in the dog and future studies are needed to improve knowledge on these pathologies in veterinary medicine, since prognosis and therapy are different.

Multiple cutaneous plasmacytosis with multilobated (clover-leaf shaped) nuclei cells in a dog

A 12‐year‐old female Shih‐tzu dog was presented with a 2‐month history of cutaneous non‐pruritic multiple ulcerated or crusted nodules of less than 1.5 cm in diameter on eyelids, lips, abdomen, groin, thighs and perianal region. Several diagnostic tests were performed, including fine needle aspiration and skin biopsy of the cutaneous nodules. Cytologic interpretation was round cell neoplasm with multilobated (clover‐leaf shaped) nuclei. Histopathology revealed round neoplastic cells with prominent anisocytosis and anisokaryosis, and numerous mitotic figures; however, the origin of the cells was not identified. Immunohistochemical evaluation indicated that these cells were positive for CD79a and MUM‐1, but negative for CD3, CD20 and Pax 5. The patient was treated with chemotherapy, and the skin condition improved. Despite good response to chemotherapy, the patient was euthanized due to poor general health.