A Peripheral Primitive Neuroectodermal Tumor with Generalized Bone Metastases in a Puppy

A peripheral primitive neuroectodermal tumor (pPNET), most consistent with a human Ewing's sarcoma, is described in a 5-month-old male Australian Shepherd puppy. The first tumor site detected was in the left frontal bone of the skull with apparent subsequent rapid metastases to multiple sites in the axial and appendicular skeleton and bone marrow, kidneys, and perihyphophyseal meninges. Radiographically, all bone lesions were lytic and there was also a humeral bone fracture. Histologically, the tumor was diagnosed as a small round blue cell tumor. At this stage, the differential diagnosis included a lymphoma, rhabdomyosarcoma, and a PNET of the peripheral nervous system. However, the cells had positive expression of triple neurofilament antigens as detected immunocytochemically. The cells were negative for a broad panel of canine-specific leucocyte cell marker antigens for desmin, smooth muscle actin, synaptophysin, and CD99. Ultrastructurally, the cells contained occasional dense core neurosecretory granules and intermediate filaments with intercellular desmosomal-like junctions and abundant glycogen clusters. Based on the age of the dog, the clinical history, the distribution of gross lesions, histologic characteristics of a small round blue cell tumor, and immunocyto-chemical and ultrastructural evidence of neuroectodermal differentiation, a diagnosis of a pPNET similar to a human Ewing's sarcoma was made.

Immunocytological confirmation of bone marrow metastases in a dog with cholangiocarcinoma

The case history of a four-year-old, male Bernese mountain dog is presented. Carcinoma cells were detected in the liver by ultrasound-guided fine-needle aspiration. Bone marrow aspirated from the iliac crest and the left femur showed a distinct infiltration by carcinoma cells. Immunocytological examination of the liver and bone marrow metastases showed a negative staining result for large spectrum cytokeratin (CK) KL1, a strong positive result for CK7 and a focal weak positive result for CK20. The dog was euthanased due to the grave prognosis. Histopathological examination revealed metastatic cholangiocarcinoma. The authors conclude that cytological and immunocytological examination of bone marrow aspirates should be used more frequently for the detection of distant metastases of carcinomas in small animal medicine.

Extradural spinal, bone marrow, and renal nephroblastoma

A 1-year-old, female intact Shetland sheepdog presented with acute onset of neurological signs. Physical examination revealed a large abdominal mass. Neurological examination revealed multifocal disease with neck pain, short-strided forelimbs, and hind-limb paresis with loss of tail and anal tone. Blood work, imaging techniques, cytopathology, and histopathology led to a diagnosis of renal, bone-marrow, and extradural spinal nephroblastoma. This report documents potential clinical and pathological manifestations of canine nephroblastoma that have not been previously reported.

Cytology of bone marrow

Cytologic examination of bone marrow aspirates can provide a wealth of diagnostic information. Practitioners should not hesitate to perform bone marrow aspirates when indicated. This article is designed to assist the practitioner in the evaluation of bone marrow aspiration biopsies. The indications for marrow evaluation, methods of sample collection, sample preparation, and cytologic examination of bone marrow are discussed. Cases are provided to demonstrate accurate interpretation of bone marrow aspirates.

Liposarcoma arising from the mandibular bone marrow in a ferret

Images