GH-Producing Mammary Tumors in Two Dogs with Acromegaly

Abstract

ABSTRACT. Two intact female dogs were admitted for growing mammary tumors. They had symptoms of acromegaly including weight gain, enlargement of the head, excessive skin folds, and inspiratory stridor. Serum concentrations of growth hormone (GH), insulinlike growth factor-I (IGF-I), and insulin were elevated in the two cases. From these findings, both dogs were diagnosed with acromegaly. In case 1, the GH, IGF-I, and insulin levels subsided after removal of the focal benign mammary tumors and ovariohysterectomy. In case 2, those levels subsided after removal of only focal mammary carcinoma. In both cases, immunohistochemical investigations for GH were positive in the mammary tumor cells but not in the normal mammary glands. We concluded that GH-producing mammary tumors caused the present acromegaly.

Spontaneous acromegaly: A retrospective case control study in German shepherd dogs

“…The effect of GH on mammary tumourigenesis in ADs may be independent of progesterone stimulation (Murai et al, 2012) as mammary carcinomas express the GH gene independent of the influence of progesterone Van Garderen et al, 1997). In one of the dogs included in our study, most of the signs of acromegaly disappeared and IGF-1 concentrations normalised only following the removal of the mammary tumours and not following ovariohysterectomy.…”

Disorders of Growth Hormone

“…The two dogs with assumed mammary-tumor derived GH-excess were a 10-year-old Miniature Dachshund and a 13-year-old Papillon, both were female-intact (Murai et al, 2012).…”

Clinical diabetes mellitus in association with diestrus-induced acromegaly in 2 bitches

“…Some bitches might even enter diabetic remission days to weeks after neutering. It has also been documented that GH and progesterone levels can normalize within hours to days after ovariohysterectomy and mastectomy [9][28] [31]. In canine and feline cases with long-lasting GH influences, remission may not be achieved.…”

“…Mammary neoplasms can also produce GH autonomously, but induction of hypersomatotropism is generally rare [31][39] [40]. In dogs with concurrent mammary neoplasms, mastectomy is highly recommended since the neoplasms can produce GH autonomously [31][39] [40]. Progesterone levels decrease rapidly after ovariohysterectomy and mastectomy followed by GH and IGF-1 [8] [28] [31] [39].…”

“…It has been shown that the vast majority of all benign and malignant mammary neoplasms also produce GH autonomously. Plasma and tissue GH and IGF-1 are higher in malignant than benign neoplasms [31] [39][40] [42]. Two cases have been reported of dogs having mammary neoplasm-derived GH-excess [31].…”