Tumor glómico

GLOMUS TUMOR IN THE CARPUS OF A DOG
Ortega J,1 Sanchís F, 1 Rosell J, 1 Bolta D, 2 Clemente F, 1 Barragán A1 and Viana D1
1Anatomic
Pathology, School of Veterinary Medicine, University CEU-UCH, Valencia, Spain
2CV
Bolta, Valencia, Spain
INTRODUCTION
The glomus tumor is a rare neoplasm arising from the glomus body cells, modified smooth muscle cells located at the arteriovenous anastomosis,
which regulate the temperature.1-3 This tumor commonly develops in the deep dermis and subcutis in the subungual region of the finger, although it
sometimes arises in other regions, including the bone, stomach, and nose.1
MATERIAL AND METHODS
A 2 cm in diameter round mass was observed in the right carpus of a 6 year old male Schnauzer (Fig. A). The mass was ulcerated and painful on
palpation. A punch biopsy was submitted to the Anatomic Pathology Service of the University CEU Cardenal Herrera for histopathological analysis.
RESULTS
Histological examination showed a non-encapsulated, well circumscribed and partially infiltrative neoplasia (Fig. B), composed round to polygonal or
spindle cells arranged in nests and bundles (Fig. C). The neoplastic cells presented distinct cell borders, small to moderate amounts of wispy
eosinophilic to clear cytoplasm, and round to oval to irregular, central, sharply defined nuclei with finely stippled chromatin and, sometimes, indistinct
nucleoli. Neoplastic cells were associated with numerous nerve branches and small blood vessels (Fig. D). In some areas, neoplastic cells were
bulging into the vascular spaces, but they did not go through the vascular wall, as they remained lined by a single layer of flat endothelium (Fig. E).
Neoplastic cells were positive for vimentin (Fig. F) and pan-actin (Fig. G and H) and negative for citokeratin.
n
v
A
B
C
D
E
F
G
H
Figure A: A 2 cm mass in the right carpus.
Figure B: Non-encapsulated and infiltrative neoplasia, H-E.
Figure C: Round to polygonal neoplastic cells, H-E.
Figure D: Neoplasia associated to vessels (v) and nerve branches (n), H-E.
n
Figure E: Neoplasia bulging into a vessel, lined by endothelim (arrow), H-E.
Figure F: Neoplastic cells are positive for vimentin.
Figure G: Neoplastic cells are positive for pan-actin.
Figure H: Neoplastic cells bulging into a vessel (same area as in Fig. E), pan-actin.
DISCUSSION
This neoplasia was diagnosed as a glomus tumor based on the histological features and immunohistochemical results. One of the main differential
diagnosis would be the cutaneous leiomyosarcoma, with similar immunohistochemical features. However, the association of the neoplasitc cells to
nerve branches and blood vessels and the bulging into the vascular spaces is more consistent with a glomus tumor.4 This neoplasia showed some
features of malignancy based on the classification for glomus tumor in human medicine, (i.e. infiltration, spindle cell component, etc.). However, after
1 month of prednisolone treatment, the mass decreased in size up to 1 cm, and it was completely removed without evidence of infiltration. This case
suggests that further studies are necessary to know the histologic features and clinical behavior of glomus tumors in veterinary medicine.
REFERENCES
1. Weiss SH, Goldblum JR. Perivascular tumors. In: Weiss SW, Goldblum JR, eds. Enzinger and Weiss’ Soft Tissue Tumors, 5th edn. Edinburgh:
Mosby, 2008: 751–67.
2. Furuya Y, Uchida K, Tateyama S. J. A case of glomus tumor in a dog. Vet Med Sci. 2006 Dec; 68(12):1339-41.
3. Park CH, Kozima D, Tsuzuki N, Ishi Y, Oyamada T. Malignant glomus tumour in a German shepherd dog. Vet Dermatol. 2009 Apr; 20(2):127-30.
4. Burns RE, Pesavento PA, McElliott VR, Ortega J, Affolter VK. Glomus tumours in the skin and subcutis of three horses. Vet Dermatol. 2011 Apr;
22(2):225-31.