Splenic myelolipoma in a dog / Mielolipoma esplênico em um cão

Myelolipoma is a benign neoplasm composed of mature adipocytes and hematopoietic elements. This tumor is rare in dogs and cats and can develop in several organs and tissues. This report describes a case of splenic myelolipoma in a dog characterizing its clinical-pathological and ultrasonography aspects. A 9-year-old, female, mixed-breed, castrated dog was referred to the veterinary hospital with increased abdominal circumference. Ultrasonography revealed splenomegaly with masses of not measurable dimensions along the entire length of the parenchyma. The spleen was removed, and a fragment was sent for histopathological analysis. Macroscopically, the spleen was enlarged, with irregularly nodular growths that project above the surface of the organ. Nodules were red with small yellow areas. Microscopically, the spleen was effaced by a well-demarcated and not encapsulated mass composed of histologically well-differentiated neoplastic adipose tissue with islands and nests of varying proportions of hematopoietic elements. Histological examination confirmed the diagnosis of myelolipoma. Myelolipomas are observed on ultrasound images as hyperechoic masses or nodules with homogeneous echo texture. Here, ultrasound appearance involved mixed echogenicity and heterogeneous echotexture, due to the mixture of fat and non-fatty material components of the tumor.(AU)

Mielolipoma é uma neoplasia composta por adipócitos maduros e elementos hematopoiéticos. Este tumor é raro em cães e gatos e pode se desenvolver em diversos órgãos e tecidos. Descreve-se um caso de mielolipoma esplênico em um cão caracterizando seu aspecto clínico-patológico e ultrassonográfico. Um canino, fêmea, castrada, SRD, de 9 anos de idade foi encaminhada para o Hospital Veterinário com um aumento na circunferência abdominal. A ultrassonografia abdominal revelou esplenomegalia com massas de dimensões imensuráveis em toda a extensão do parênquima. Foi realizada esplenectomia total e um fragmento do baço foi encaminhado para análise histopatológica. Macroscopicamente o baço estava aumentado de tamanho, com crescimentos nodulares irregulares que se projetam acima da superfície do órgão. Os nódulos eram vermelhos com pequenas áreas amarelas. Microscopicamente foi observada uma massa bem demarcada e encapsulada composta por tecido adiposo neoplásico bem diferenciado, com ilhas e ninhos de elementos hematopoiéticos de proporção variada. O diagnóstico foi confirmado pelo exame histopatológico. Mielolipomas são observados nas imagens ultrassonográficas como massas hiperecóicas ou nódulos com ecotextura homogênea. Neste caso, o achado ultrassonográfico mostrou ecogenicidade mista e ecotextura heterogênea, provavelmente devido à mistura dos componentes do tumor com material gorduroso e não gorduroso.(AU)

Hepatic myelolipomas in Callimico goeldii (Thomas, 1904) kept in captivity

Myelolipoma is an unusual benign neoplasm in veterinary medicine. This work intended to report the occurrence of hepatic myelolipomas in Neotropical primates of the Callimico goeldii species kept in captivity. These cases were diagnosed during necropsy in a survey on liver neoplasms in the period of 2004 to 2008. Two cases were found in adult male, and two in adult female animals. The diagnoses were obtained through data analysis of necropsy records, pathological examination of the cases, and histological confirmation. Three (75%) of the animals showed clinical signs of progressive weight loss, and two (50%) of them exhibited regional abdominal bloating. The livers had protrusions of pale yellow color on the surface of all lobes. Histologically, the tumors were formed by mature myeloid tissue with high hematopoietic cellularity, represented by the megakaryocytes and meroblastic cells and immature erythroblasts. We conclude that non-human primates of the Callimico goeldii species might have predisposition for liver myelolipoma, which are neoplasms that can lead to the failure and destruction of this organ.

Hepatic myelolipomas in Callimico goeldii (Thomas, 1904) kept in captivity

Myelolipoma is an unusual benign neoplasm in veterinary medicine. This work intended to report the occurrence of hepatic myelolipomas in Neotropical primates of the Callimico goeldii species kept in captivity. These cases were diagnosed during necropsy in a survey on liver neoplasms in the period of 2004 to 2008. Two cases were found in adult male, and two in adult female animals. The diagnoses were obtained through data analysis of necropsy records, pathological examination of the cases, and histological confirmation. Three (75%) of the animals showed clinical signs of progressive weight loss, and two (50%) of them exhibited regional abdominal bloating. The livers had protrusions of pale yellow color on the surface of all lobes. Histologically, the tumors were formed by mature myeloid tissue with high hematopoietic cellularity, represented by the megakaryocytes and meroblastic cells and immature erythroblasts. We conclude that non-human primates of the Callimico goeldii species might have predisposition for liver myelolipoma, which are neoplasms that can lead to the failure and destruction of this organ.(AU)

Mielolipoma de adrenal funcional em um cão / Functional adrenal myelolipoma in a dog

Background: Myelolipomas are benign tumors composed of a mixture of fat and hematopoietic tissue similar to the bone marrow. They are rare tumors in humans and dogs, and occur generally in the spleen, liver, spinal canal and in the adrenal glands. When they develop in the adrenal glands they feature non-secretory and endocrinologically inactive characteristics, usually without clinical signs or other dysfunctions. Thus, they are often an incidental finding during necropsy. This paper aims to describe a case of functional adrenal gland myelolipoma and spleen myelolipoma in a female dog with clinical signs and laboratory tests compatible with hyperadrenocorticism.Case: A 12 year-old female dog, undefined breed, was treated at the Hospital Unit for Companion Animals of the Pontifical Catholic University of Paraná (PUCPR), São José dos Pinhais, Paraná, Brazil, with polyuria, polydipsia, polyphagia, cutaneous hypotonia and central obesity. Blood tests showed hypercholesterolemia and increased alkaline phosphatase; urinalysis identified isostenuria with proteinuria; and ultrasound and MRI of the abdomen indicated right adrenomegaly, with heterogeneous characteristics, without invasion of attached blood vessels and splenic nodules. The low dose dexamethasone suppression test was performed which confirmed hyperadrenocorticism. The animal was submitted to adrenalectomy and splenectomy, and tissue specimens were obtained for histopathological examination, which revealed mature adipocytes and hematopoietic elements in different phases of maturation, compatible with adrenal and spleen myelolipoma. After surgical treatment, there was a progressive improvement of the clinical manifestations and laboratory abnormalities of hypercortisolemia, without recurrence during one year.[...](AU)

Mielolipoma de adrenal funcional em um cão / Functional adrenal myelolipoma in a dog

Background: Myelolipomas are benign tumors composed of a mixture of fat and hematopoietic tissue similar to the bone marrow. They are rare tumors in humans and dogs, and occur generally in the spleen, liver, spinal canal and in the adrenal glands. When they develop in the adrenal glands they feature non-secretory and endocrinologically inactive characteristics, usually without clinical signs or other dysfunctions. Thus, they are often an incidental finding during necropsy. This paper aims to describe a case of functional adrenal gland myelolipoma and spleen myelolipoma in a female dog with clinical signs and laboratory tests compatible with hyperadrenocorticism.Case: A 12 year-old female dog, undefined breed, was treated at the Hospital Unit for Companion Animals of the Pontifical Catholic University of Paraná (PUCPR), São José dos Pinhais, Paraná, Brazil, with polyuria, polydipsia, polyphagia, cutaneous hypotonia and central obesity. Blood tests showed hypercholesterolemia and increased alkaline phosphatase; urinalysis identified isostenuria with proteinuria; and ultrasound and MRI of the abdomen indicated right adrenomegaly, with heterogeneous characteristics, without invasion of attached blood vessels and splenic nodules. The low dose dexamethasone suppression test was performed which confirmed hyperadrenocorticism. The animal was submitted to adrenalectomy and splenectomy, and tissue specimens were obtained for histopathological examination, which revealed mature adipocytes and hematopoietic elements in different phases of maturation, compatible with adrenal and spleen myelolipoma. After surgical treatment, there was a progressive improvement of the clinical manifestations and laboratory abnormalities of hypercortisolemia, without recurrence during one year.[...]

Hepatic myelolipoma in two Goeldi's monkeys from South America held captive.

Two cases of hepatic myelolipoma in Goeldi's monkeys from South America are described. One was a female evaluated due progressive abdominal distension. Ultrasound and computed tomography detected hepatic mass. Partial hepatectomy was performed, but the monkey died after surgery. Case 2 was a male that died suddenly, showing non-specific clinical signs.