A morphometric analysis of tumoral Langerhans cells and activated macrophages was conducted using canine cutaneous tumors (65 cases of canine cutaneous histiocytoma and 7 cases of pyogranuloma). The histiocytic origin of the tumor cells was confirmed using immunohistochemistry. The parameters of the morphometric analysis included cellular and nuclear size and shape and the nuclear: cytoplasmic ratio; the variability of these features was calculated separately for each tumor. The canine cutaneous histiocytoma group was divided into four stages of regression depending on the intensity of the lymphocytic infiltration. Statistical analysis revealed that the anisocytosis, anisokaryosis and cellular pleomorphism of tumoral Langerhans cells increased, while the cellular circularity and nuclear:cytoplasmic ratio decreased with tumor regression. Activated macrophages of the pyogranuloma were significantly larger, and had larger nuclei, than tumoral Langerhans cells. Furthermore, these activated macrophages showed greater anisocytosis and anisokaryosis and a lower nuclear: cytoplasmic ratio than tumoral Langerhans cells in the first stages of tumor regression. These results indicate that tumoral Langerhans cells undergo morphologic changes during the regression of canine cutaneous histiocytoma, reflecting their maturation and differentiation. Morphometry can be a useful method for distinguishing activated macrophages from tumoral Langerhans cells.
Baines SJ, Bujdoso R, Backlaws BA, McInnes E, Moore PF, McConnel IM (2000) Maturation states of dendritic cells in canine cutaneous histiocytoma. Vet Dermatol 11 (Suppl 1): 9-10.
Ciobotaru E, Militaru M, Soare T, Mocanu J, Bartoiu A (2004) Canine cutaneous histiocytoma: morphology and morphometry. Vet Dermatol 15 (Suppl 1): 62.
Cockerell GL, Slauson DO (1979) Patterns of lymphoid infiltrate in the canine cutaneous histiocytoma. J Comp Pathol 89: 193-203.
Coomer AR, Liptak JM (2008) Canine histiocytic diseases. Compend Contin Educ Vet 30: 202-216.
De Andrade Waldemarin KC, Beletti ME, Da Fontoura Costa L (2004) Nuclear morphometry of neoplastic cells as a method for diagnosis of histiocytoma, mastocytoma and transmissible venereal tumor in dogs. Real-Time Imaging 10: 197-204.
Fernandez NJ, West KH, Jackson ML, Kidney BA (2005) Immunohistochemical and histochemical stains for differentiating canine cutaneous round cell tumors. Vet Pathol 42: 437-445.
Kipar A, Baumga¨rtner W, Kremmer E, Frese K, Weiss E (1998) Expression of major histocompatibility complex class II antigen in neoplastic cells of canine cutaneous histiocytoma. Vet Immunol Immunopathol 62: 1-13.
Lee Gross T, Ihrke PJ, Walder WJ, Affolter VK (2005) Skin diseases of the dog and cat. Clinical and histopathologic diagnosis, 2nd ed., Blackwell Science Ltd, Oxford.
McGavin MD, Zachary JF (2012) Pathologic basis of veterinary disease, 5th ed., Mosby Elsevier, St Louis.
Mellman I, Steinman RM (2001) Dendritic cells: specialized and regulated antigen processing machines. Cell 106: 255-258.
Moore PF, Schrenzel MD, Affolter VK, Olivry T, Naydan D (1996) Canine cutaneous histiocytoma is an epidermotropic Langerhans cell histiocytosis that expresses CD1 and specific beta 2-integrin molecules. Am J Pathol 148: 1699-1708.
Murphy GF, Messadi D, Fonferko E, Hancock WW (1986) Phenotypic transformation of macrophages to Langerhans cells in the skin. Am J Pathol 123: 401-406.
Pires I, Queiroga FL, Alves A, Silva F, Lopes C (2009) Decrease of E-cadherin expression in canine cutaneous histiocytoma appears to be related to its spontaneous regression. Anticancer Res 29: 2713-2717.
Pires I, Rodriques P, Alves A, Queiroga FL, Silva F, Lopes C (2013) Immunohistochemical and immunoelectron study of major histocompatibility complex class-II antigen in canine cutaneous histiocytoma: its relation to tumor regression. In Vivo 27: 257-262.
Schwens Ch, Thom N, Moritz A (2011) Reactive and neoplastic histiocytic diseases in the dog. Tierarztl Prax Ausg K Kleintiere Heimtiere 39: 176-190.
Simeonov R, Simeonova G (2006) Computerized morphometry of mean nuclear diameter and nuclear roundness in canine mammary gland tumors on cytologic smears. Vet Clin Pathol 35: 88-90.
Smitha T, Sharada P, Girish HC (2011) Morphometry of the basal cell layer of oral leukoplakia and oral squamous cell carcinoma using computer-aided image analysis. J Oral Maxillofac Pathol 15: 26-33.
Strefezzi R de F, Xavier JG, Cata˜o-Dias JL (2003) Morphometry of canine cutaneous mast cell tumors. Vet Pathol 40: 268-275.
Weiss DJ (2001) Cytologic evaluation of benign and malignant hemophagocytic disorders in canine bone marrow. Vet Clin Pathol 30: 28-34.
Wright-Browne V, McClain KL, Talpaz M, Ordonez N, Estrov Z (1997) Physiology and pathophysology of dendritic cells. Hum Pathol 28: 563-579.