Primary small intestinal lymphangiosarcoma in a dog presenting with a segmental partial mesenteric volvulus

A 3-year-old Great Dane presented with a history of chronic vomiting and diarrhoea. Abdominal computed tomography followed by exploratory laparotomy revealed a perforated, segmental partial mesenteric volvulus, affecting an abnormal section of distal jejunum, which was resected. Histopathology and immunohistochemistry results were consistent with jejunal lymphangiosarcoma. This case represents the first report of primary small intestinal lymphangiosarcoma in dogs and the importance of immunohistochemistry for definitive diagnosis.

Feline ventral abdominal wall angiosarcoma: haemangiosarcoma or lymphangiosarcoma? Clinical and pathological characteristics in nine cases

OBJECTIVES

Angiosarcomas are rare malignant mesenchymal neoplasms of endothelial cell origin with a predilection to the ventral abdominal wall in cats. Larger case series describing this entity are lacking.

METHODS

Two referral centre laboratory databases were searched for angiosarcoma of the ventral abdominal wall. Nine cases with a histological diagnosis were included. Immunohistochemistry (factor VIII and PROX-1 antibodies) was used to phenotype them as haemangiosarcoma or lymphangiosarcoma.

RESULTS

All cats presented with a ventral abdominal mass, five of which were producing a serosanguinous discharge. Eight underwent tumour staging and pulmonary metastases were suspected in one cat (but not histologically confirmed). With histopathology alone, a diagnosis of angiosarcoma and lymphangiosarcoma was made in four and five cases, respectively. After immunohistochemistry, five cases had a haemangiosarcoma phenotype and four had a lymphangiosarcoma phenotype, including two cases of lymphangiosarcoma that were reclassified as hemangiosarcoma. Eight cats received treatment (either surgery with or without adjuvant therapies or medical management alone). Six cats were euthanased due to local disease progression. The median survival time for haemangiosarcoma was 166 days (range 137-381), and for lymphangiosarcoma it was 197 days (range 67-208). Two cats with haemangiosarcoma remained alive for a follow-up period of 329 and 580 days, respectively.

CONCLUSIONS AND RELEVANCE

Feline ventral abdominal angiosarcomas are rare locally aggressive neoplasms. While histology often provides a diagnosis of angiosarcoma, immunohistochemistry is ultimately required to differentiate between haemangiosarcoma and lymphangiosarcoma phenotypes. Further studies are required to evaluate whether the different phenotypes have an impact on treatment response and outcome.

Primary Lymphangiosarcoma of the Urinary Bladder in a Dog

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

Successful management of lymphangiosarcoma in a puppy using a tyrosine kinase inhibitor

A puppy was diagnosed with lymphangiosarcoma associated with lymphedema based on lymphography and histopathology. The lesions resolved after toceranib therapy, and the dog remains in remission 1 year later. This is the first report of a successful outcome following oral toceranib as first-line therapy for lymphangiosarcoma in a dog.

Lymphangiosarcoma in a cat

This report describes a 5-year-old female cat with lymphangiosarcoma arising within the dermis and subcutis of the caudal mammary region. The mass presented as a large, poorly demarcated and fluctuant swelling with bruising of the overlying skin. Histopathologically, the dermis and subcutis in the affected region were diffusely oedematous, haemorrhagic, and infiltrated by plump spindle cells that formed irregular vascular clefts and cavernous channels. Neoplastic cells were aligned in one or more layers along oedematous collagenous trabeculae. The vascular clefts and channels contained only a few or no erythrocytes. The neoplastic cells had moderate to marked nuclear pleomorphism and prominent nucleoli. Lymphocytes and plasma cells were scattered throughout the neoplasm and the adjacent soft tissues. Immunohistochemical labelling revealed the neoplastic cells to express vimentin, factor VIII-related antigen and the lymphatic endothelial cell marker PROX-1, but the cells did not express cytokeratin. The nuclei of many neoplastic cells expressed the proliferation marker Ki67. These histopathological and immunohistochemical findings confirmed the diagnosis of lymphangiosarcoma. This is the first report describing the usefulness of expression of PROX-1 for differentiating between angiosarcoma of lymphatic and vascular origin in cats.

Lymphangiosarcoma in two cats

Lymphangiosarcoma is a malignant neoplasm of the lymphatic endothelium that is rare in cats. This report describes two cases of feline lymphangiosarcoma that originated in the distal limb, causing intractable lymphoedema and serosanguineous discharge with ecchymoses in local and distant sites. In association with the neoplasia, one cat had cortical bone lysis of multiple metacarpal bones of the affected limb and the other had severe immune-mediated haemolytic anaemia (IMHA). The disease in both cases affected young cats and progressed rapidly. Persistent distal limb lymphoedema with serosanguineous discharge is suggestive of lymphangiosarcoma especially when local or distal ecchymoses are evident.

Fat necrosis simulating recurrent neoplasia following external beam radiotherapy in a dog

A 4.5-year-old neutered male dog was diagnosed with incompletely excised well-differentiated lymphangiosarcoma in the right inguinal subcutaneous region. The mass had metastasized to the right hypogastric and medial iliac lymph nodes. Surgery followed by definitive radiation therapy was administered to the primary site and the sites of metastasis. The dog had a complete response to radiotherapy, and minimal acute side effects. Doxorubicin was administered after radiotherapy. Approximately 4 months following radiation therapy, the dog developed a mass, presumed recurrent tumor, in the original site. In a biopsy only steatitis and fibrosis were found. The mass continued to grow and conservative surgical excision was elected. Histopathologically the diagnosis was fat necrosis and steatitis, with a microscopic focus of lymphangiosarcoma. Fat necrosis is an uncommon sequelum to breast irradiation in people and also appears to be rare in animals. Fat necrosis should be considered as a differential diagnosis when recurrent tumor is suspected in a previously irradiated subcutaneous site in a dog.

IMAGING FINDINGS IN PANCREATIC NEOPLASIA AND NODULAR HYPERPLASIA IN 19 CATS

Pancreatic neoplasia in cats is rare and associated with a poor prognosis, but pancreatic nodular hyperplasia is a common incidental finding. The purpose of this study was to describe radiographic and ultrasonographic findings in cats with pancreatic neoplasia or nodular hyperplasia. Fourteen cats (age 3-18 years) were diagnosed with malignant pancreatic tumors: carcinoma/adenocarcinoma (n = 11), lymphoma (n = 1), squamous cell carcinoma (n = 1), and lymphangiosarcoma (n = 1). The most common radiographic findings were an abdominal mass or mass effect (6/6) and lack of serosal margin detail (4/6). On ultrasound, the most common finding was a focal pancreatic mass or nodule, with a size range from 0.4 cm to more than 7.0 cm (8/14). Lymphadenopathy (7/14) and abdominal effusion (7/14) were frequently seen. Five cats (age 10-16 years) with adenomatous/nodular hyperplasia had an abdominal mass or mass effect as the most common radiographic finding (3/3). On ultrasound, all cats had multiple hypoechoic nodules between 0.3 and 1.0 cm associated with the pancreas. Other common findings were pancreatic thickening (2/5), lymphadenopathy (2/5), and abdominal effusion (2/5). The only imaging finding unique to malignant pancreatic tumors was the presence of a single pancreatic nodule or mass exceeding 2cm in at least one dimension (4/14). Although there was a tendency for neoplastic lesions to manifest as single larger lesions and for nodular hyperplasia to manifest as multiple smaller lesions, there was overlap of the imaging findings in both entities. Radiographs and ultrasound can complement but not replace cytology and histopathology in the diagnosis of feline pancreatic neoplasia.

Lymphangiosarcoma of dogs: a review

Lymphangiosarcoma in dogs, an extremely rare tumour with only 16 cases reported in the literature, is reviewed. Lymphangiosarcoma in humans, also very rare, and known in post-mastectomy, chronically-lymphoedematous patients as 'Stewart-Treves' syndrome, is briefly outlined, as well as the various other causes of lymphoedema, both primary and secondary, which usually precede malignancy. Comparisons between human and canine lymphoedema are made when such references were found. The genetic links to primary lymphoedema and the manifestation thereof in humans are mentioned. Lymphangiosarcoma in the majority of human and canine patients is an aggressively malignant tumour with few patients surviving despite various attempted treatments. The tumour most commonly arises in the subcutaneous tissues and rapidly invades underlying tissues and may spread widely internally via haematogenous and lymphatic routes, with frequent pleural and chest involvement. The tumour has been reported mostly in medium- to large-breed dogs, in slightly more males than females, and in an age-range of 8 weeks to 13 years, with more cases aged 5 years and older. Methods of diagnosis, with the variations encountered, including routine histopathology, immunohistochemistry, electron microscopy, tissue culture characteristics and endothelial expression of glycocongugates, are discussed.

Lymphangiosarcoma in a 3.5-year-old Bullmastiff bitch with vaginal prolapse, primary lymph node fibrosis and other congenital defects : clinical communication

Lymphangiosarcoma is an extremely rare tumour in dogs with only 16 cases reported in the literature. Lymphoedema, whichmaybe primary due to defects in the lymphatic system, or secondary to various other pathologies, often precedes malignancy. Of the 16 canine reports, only 1 dog was confirmed as having had prior primary lymphoedema due to aplasia of the popliteal lymph nodes. A case of lymphangiosarcoma is described in a 3.5-year-old purebred, Bullmastiff bitch which presented with vaginal blood 'spotting' for 3 weeks after cessation of oestrus, during which intromission by the male had been unsuccessful. During ovariohysterectomy a large multicystic, proliferative, spongy, fluid-filled, brownish-red mass surrounding the cervix and projecting into the abdominal space was removed with the cervix, and a diagnosis of lymphangiosarcoma made on histological and electron microscopic examination of the tissue. Ultrastructurally, no basement membrane or pericytes were found, only some of the neoplastic endothelial cells were linked by tight junctions while there were gaps between others, and neither micropinocytotic vesicles nor Weibel-Palade bodies occurred in the cells examined.Very few of the endothelial cells lining the many interlinking, tortuous maze of channels, stained slightly positive immunohistochemically for factor VIII-related antigen. The channels were filled mostly with serous fluid, and occasionally mixed leucocytes and some erythrocytes. The endothelium was often associated with underlying blocks of collagenous material, as well as looselyarranged aggregates of lymphocytes, other mononuclear cells and occasional neutrophils in the connective tissue septae and more prominently perivascularly. The bitch was discharged on antibiotic treatment but returned 2 weeks later with apparent prolapsed vagina which failed to reduce over the next week. Laparotomy revealed the tumour to have spread extensively in the caudal abdomen to involve the broad ligament and the ventral rectal serosa, and the 'prolapsed' tissue was found to be expanded vaginal wall. The bitch was euthanased and necropsied, Histological examination confirmed lymphangiosarcomatous invasion of the submucosal and muscular layers of the retroperitoneal, traumatised, prolapsed part of the vagina, the urethra and the ventral rectal wall. The broad ligament was diffusely invaded with tumour which had proliferated into the caudal abdominal space, and 3 small intra-trabecular foci of tumour were found in the right popliteal lymph node near the hilus. Mitotic figures were generally scarce. There was mild subcutaneous oedema of the ventral trunk extending from the axillae to the inner proximal thighs, which had not been evident clinically, and the lymph nodes (peripheral more so than internal) microscopically showed marked trabecular and perivascular fibrosis especially in hilar regions. Other congenital defects were hepatic capsular and central venous fibrosis with lymphatic duplication and dilatation in all areas of connective tissue, ventrally-incongruous half-circular tracheal rings, and multifocal renal dysplasia affecting the right kidney. There was locally-extensive subacute pyelonephritis of the left kidney.

Cutaneous lymphangiosarcoma in a young dog: clinical, anatomopathological and lectinhistochemical description

Lymphangiosarcoma is a rare tumour in domestic animals arising from lymphatic endothelial cells. Occasionally, microscopic differentiation with haemangiosarcoma may be difficult. The aim of the present study was to describe a lymphangiosarcoma in a 1-year-old female Doberman Pinscher dog and to characterize its lectinhistochemical binding pattern as compared with that of haemangiosarcoma. The dog was presented because of a cutaneous painful swelling located in the left axilla. Histological diagnosis confirmed lymphangiosarcoma. The dog was killed. Necropsy revealed mediastinal lymph nodes' involvement. Twenty lectins were tested in tissue sections of this case as well as in four haemangiosarcomas from other dogs. Staining intensity was issued upon optical density determinations. Percentage of lectinhistochemical staining area was also conducted. RCA-I showed the most intense and wide distributed labelling pattern for lymphangiosarcoma. PHA-E was the counterpart for haemangiosarcoma. Should similar results be obtained in further studies, such differences could aid in the differential diagnosis between lymphangiosarcoma and haemangiosarcoma when histological pictures were not conclusive.

Lymphangiosarcoma in a dog treated with surgery and chemotherapy

A large subcutaneous mass at the left cervical site in a 9-year-old male Siberian husky was removed surgically. Histopathologically, the mass was mainly consisted of a proliferation of spindle-shaped neoplastic cells arranging in solid sheath and partially vascular channels containing few blood cells. The tumor cells exhibited highly invasive activity to the surrounding tissues. In addition, the tumor cells were immunopositive for Factor VIII-related antigen. On the basis of these findings, the tumor was diagnosed as lymphangiosarcoma. Recurrent mass was noticed 3 weeks after surgery but completely disappeared after the doxorubicin treatment. Neither recurrence nor metastasis was observed for 9 months after the remission.

Feline lymphangiosarcoma--definitive identification using a lymphatic vascular marker

Three cases of feline exudative dermatitis associated with lymphangiosarcoma are described. The animals, an 11-year-old, neutered male and two 10-year-old, neutered female short hair European cats, presented with a 2-month history of transparent liquid oozing from the skin of the groin and caudal abdomen. On physical examination the neutered male cat and one of the females were slightly depressed and showed loss of weight. Skin lesions were similar in all cats and characterized by the presence of alopecia and moist dermatitis in the ventral abdomen, groin and inner thigh. The hair at the periphery appeared matted by the fluid. In all three cases, histopathological examination of skin biopsies from the abdomen identified poorly defined neoplasia involving dermis and subcutis, characterized by proliferation of spindle cells aligned along pre-existing collagen bundles. The dissection of collagen bundles gave rise to irregular shaped anastomosing, often blind-ending vascular channels and trabeculae. Vascular spaces were mostly optically empty. These histological features were strongly suggestive of lymphangiosarcoma. Neoplastic cells were positive for the blood vascular marker Von Willebrand factor, and a lymphatic vascular marker LYVE-1 (Lymphatic Vessel Endothelial receptor - 1), demonstrating the mixed vascular origin of the tumour. Ultrastructural findings confirmed the final diagnosis of lymphangiosarcoma.

Metastatic lymphangiosarcoma in a horse

A lymphangiosarcoma with metastases was found in a horse that presented with respiratory distress and edema in the ventral thorax and abdomen. The necropsy revealed diffuse edema in the subcutaneous connective tissue. Mediastinal, mesenteric, iliac, and renal lymph nodes were enlarged and white with soft, yellowish necrotic areas. Histologic examination revealed numerous channels and disorganized vessels lined by large polyhedral, polymorphic cells. Tumor metastases were observed in the spleen, lungs, and kidneys. Immunohistochemical evaluation of the tumor cells demonstrated positive staining for factor VIII, vimentin, and keratin. Laminin was scarce, and collagen IV staining was negative, consistent with a discontinuous or absent basement membrane.

Chylothorax in a dog with pulmonary lymphangiosarcoma

Lymphangiosarcoma of the pulmonary pleura was found to be the cause of persistent chylothorax in an eight-year-old, intact male golden retriever. After a two-month course of medical management, a lymphangiogram and thoracic duct ligation were performed with the objective of decreasing further effusion. At surgery, gross lung pathology was biopsied and yielded a histopathological diagnosis of pulmonary pleural lymphangiosarcoma. A relatively rare tumor, lymphangiosarcoma of the pulmonary pleura has not previously been documented as a source of chylothorax in the dog.

Lymphangiosarcoma in a horse

A 15-year-old Dutch Warmblood mare presented with respiratory distress and anorexia. Clinical examination revealed liquothorax and an abdominal mass. At necropsy, an infiltrating tumour was found in the visceral trunk, continuing through the diaphragm into the mediastinum. Histopathology, immunohistochemistry and electronmicroscopy showed empty channels lined by atypical endothelial cells, and neoplastic cells in a disorganized pattern, consistent with the diagnosis of a lymphangiosarcoma.

Lymphangiosarcomas in cats: a retrospective study of 12 cases

Clinical, macroscopic, and histologic features of 12 lymphangiosarcomas in cats are described. Nine tumors were located in the subcutaneous tissue at the caudoventral abdominal wall (eight cats) or in the neck (one cat). The remaining three cats had lymphangiosarcomas around the cranial mesenteric artery (two cats) or precardial in the mediastinum (one cat). Macroscopically, the tumors were noncircumscribed, white, edematous, and intermixed with fat tissue. Histologic features varied from cleft-forming and cavernous growth to papilliform and solid patterns. Follow-up data were available for seven cats with subcutaneous lymphangiosarcomas. All these cats died or were euthanatized within 6 months after surgery because of poor wound healing, local recurrence, or distant metastases. The cats with abdominal or thoracic masses were either euthanatized at surgery or within 6 months after the first surgery because of recurrent chylothorax, chyloperitoneum, or distant metastases.

Lymphangiosarcoma in a dog presenting with massive head and neck swelling

A three-year-old, neutered male Chesapeake Bay retriever was presented for acute onset of severe, progressive swelling of the head, neck, and cranial trunk. Diffuse lymphangiosarcoma involving the superficial and deep dermis and subcutaneous tissue was observed on skin biopsies. Lymphangiosarcoma is a rarely reported tumor of the lymphatic system in dogs and cats. The importance of obtaining skin biopsies in animals with acute edema of unknown etiology is emphasized. Additionally, neoplasia should be considered as a potential diagnosis in a dog with an acute onset of edema.

Intraabdominal lymphangiosarcoma in a Fischer-344 rat

A Sarcoma arising in the abdominal cavity in an aged Fischer-344 rat was studied by immunohistochemistry and electron microscopy. The white-yellow soft mass was located on the lumbosacral vertebrae, compressing adjacent parenchymal organs. The tumor was made up of spindle shaped cells situated in a background of myxoid substance and a small amount of reticulin and collagen fibers. The tumor cells grew in a loose storiform pattern and often adhered to each other by their cell processes to form ovoid or slitlike spaces. Immunohistochemically, the tumor cells were strongly positive for vimentin but negative for keratin, macrophage ED1 antigen, alpha-smooth muscle actin, Factor VIII-related antigen, and S100 protein. Electron microscopy demonstrated the endothelial differentiation of the tumor cells, such as occasional luminal spaces, a small number of micropinocytotic vesicles, and interdigitating junctions with desmosomes between cell processes of adjacent cells. Furthermore, its endothelial origin was suggested by the presence of electron-dense rods resembling Weibel-Palade bodies. Instead of a definitive basement lamina surrounding the tumor cells, there were extracellular thin "anchoring filaments" that were attached to the cell surface at areas of increased electron density. These findings indicate that the tumor is of lymphatic vessel type rather than blood vessel type.

Disseminated lymphangiosarcoma in a dog

This case is unusual due to its extended clinical course. Clinical, histopathological, and immunohistochemical findings are presented.

Chylothorax and chylous ascites in a dog with mediastinal lymphangiosarcoma

A 10-year-old, male toy poodle presented for evaluation of a progressively worsening, harsh, nonproductive cough. Chylous pleural effusion, lymphopenia, thrombocytopenia, normoblastemia, and recurrent subcutaneous bruising were diagnosed. Surgical exploration of the cranial mediastinum revealed extensive, redundant connective tissue which was confirmed by histopathology to be mediastinal lymphangiosarcoma (LAS). During surgical placement of a fenestrated silastic mesh for passive pleuroperitoneal drainage, chylous ascites also was diagnosed. The patient was euthanized two days postoperatively due to persistent chylothorax. The etiopathogenesis of chylothorax and chylous ascites are discussed. Previous case reports of lymphatic endothelial neoplasia are reviewed.

Lymphangiosarcoma in a young dog

Lymphangiosarcoma was diagnosed from biopsy material obtained from an 8-week-old puppy with a progressively enlarging subcutaneous inguinal swelling. Histologically, the tumor was composed of endothelial cells immediately adjacent to large collagen bundles. Tumor cells formed irregular vascular channels which extended along the connective tissue investments of small vessels and nerves of the subcutis and deep dermis. Similar neoplastic tissue extensively infiltrated an inguinal lymph node. Neoplastic cells were immunohistochemically stained for factor 8-related antigen and were weakly positive when compared with several hemangiomas and hemangiosarcomas. Transmission electron microscopy revealed numerous micropinocytotic vesicles and a continuous basal lamina. The puppy was euthanatized at 8 months of age due to severe septic polyarthritis. Lymphangiosarcoma was documented at the site of the original tumor as well as in the axillary lymph node at necropsy.

Lymphangiosarcoma in a dog

Lymphangiosarcoma was seen in the subcutis of right chest in a 11-year-old female Poodle. No metastasis was observed clinically. Tumor cells were vimentin positive and formed irregular space or slit without erythrocytes in the tumor tissue. Lymphocytic foci and edema were seen in the stroma. Only a few tumor cells had factor VIII-related antigen. Electronmicroscopically, tumor cells did not accompany with basement membrane and intercellular junctional complex.

Chylous ascites in cats: nine cases (1978-1993)

Medical records of 9 cats with chylous ascites that underwent exploratory celiotomy were reviewed. In 7 cats, chylous ascites was associated with intra-abdominal neoplasia: 4 cats had an unresectable tumor (hemangiosarcoma, 3 cats; paraganglioma, 1 cat) within the mesenteric root; 2 had malignant lymphoma of the small intestine and mesenteric lymph nodes; and 1 had lymphangiosarcoma of the abdominal wall. In 2 cats, chylous ascites was associated with nonneoplastic diseases: 1 cat had severe biliary cirrhosis and an extrahepatic portosystemic shunt; the other had steatitis caused by vitamin E deficiency. Three cats were euthanatized or died at the time of surgery, and 5 cats were euthanatized within 3 months of surgery. One cat with malignant lymphoma responded well to chemotherapy and lived for 14 months after surgery.

Ocular lymphangiosarcoma in a cow

Ocular lymphangiosarcoma was diagnosed in a Holstein cow with a progressively enlarging limbal mass. The cow was treated by exenteration. The cow survived for 2 years without clinical signs of recurrence. Lymphangiosarcoma is a vascular neoplasm that rarely has been reported in domestic animals. In other species, it has a high rate of metastasis and is associated with poor long-term survival.

Lymphangiosarcoma and haemangiosarcoma in a cat

Ultrastructural findings in a feline ventral abdominal vascular tumour showed lack of basal lamina, few micropinocytotic vesicles and intercellular junctions and a discontinuous endothelial cell layer. A splenic cyst had a continuous basal lamina, numerous micropinocytotic vesicles and intercellular junctions and a continuous endothelial cell layer. These findings were compatible with diagnosis of lymphangiosarcoma (ventral abdomen and metastases) and haemangiosarcoma (splenic cyst).

Lymphangiosarcoma in two cats

Cutaneous tumours consisting of irregular empty anastomosing spaces lined by spindle cells were diagnosed as lymphangiosarcoma in two cats. The tumour cells exhibited the characteristic lining up along pre-existing collagen and muscle fibres. Because of the small number of cases of lymphangiosarcoma in cats, conclusions regarding biological behaviour or breed incidence are not made.

Canine angiosarcoma (lymphangiosarcoma)

After injury to the left foreleg, a 2 1/2-year-old Great Dane bitch developed severe oedema of the limb, which did not respond to pressure bandaging or a proteolytic agent. Skin breakdown occurred over the metacarpal region and lymph could be expressed from this lesion. The oedema spread, anaemia and dyspnoea developed and the animal died of respiratory insufficiency 55 days after the initial injury. Autopsy showed widespread infiltration of subcutis, fascial planes and some muscles of the leg by invasive cords and sheets of small endothelial-type cells which formed channels sometimes filled with blood. There was widespread diffuse metastatic neoplasm throughout the lung but no cavernous blood sinus formation. There were small metastases in local lymph nodes, kidney, bone marrow and spleen. It was concluded that the injury made obvious an oedema caused by pre-existing angiosarcoma.