Figure 8 - uploaded by Annette Noel Smith
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Transmission electron micrograph of stromal myofibroblast. Cells are embedded in a variably abundant collagenous matrix (asterisk) and have abundant rough endoplasmic reticulum, occasional focal dense bodies (arrowhead), and electron dense attachment plaques (arrow). Uranyl acetate-lead citrate staining.
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An intact, 8-year-old, male Golden Retriever dog was presented for evaluation of a nasal mass and approximately 30 firm, raised, variably ulcerated dermal and subcutaneous masses. Histopathology of both nasal and multiple skin masses revealed multiple nonencapsulated, infiltrative masses comprising clusters, anastomosing trabeculae, and packets of...
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... cells and rare membrane-bound dense core structures consistent with neurosecretory granules (Fig. 7). The adjacent myofibroblastic cells were surrounded by collagen fibrils and had abundant rough endoplasmic reticulum; multiple plasma membrane attachment plaques; intracytoplasmic, peri- pherally located actin filaments; and focal dense bodies (Fig. ...
Citations
... Among the mesenchymal tumors, chondrosarcoma is the most reported (Ogilvie & LaRue 1992;Wilson & Dungworth 2002). Rarely reported tumors are melanoma (Hicks & Fidel 2006), olfactory neuroblastoma (Brosinski et al. 2012), neuroendocrine carcinoma (Sako et al. 2005;Ninomiya et al. 2008;Koehler et al. 2012), and lymphosarcoma (Robertson 1998). Nasal tumors are locally aggressive with a tendency to infiltrate the underlying tissues, to extend into the forebrain or to destroy the septum causing a bilateral involvement. ...
This chapter discusses physiology, sampling, processing, and cytopathologic assessment of the upper and lower respiratory tracts. Description and interpretation of normal cytology, common respiratory cytologic artifacts, cytopathologic cellular responses to injury, and inflammatory and neoplastic cytopathologic disorders in the respiratory tracts of dogs and cats are emphasized.
The upper respiratory tract (URT) consists of the nose with nasal passages and paranasal sinuses, the pharynx, and the larynx above the vocal cords. Physiological functions of the URT include warming, filtering, and humidifying inspired air prior to contact with the more delicate mucus membranes of the caudal upper and lower airways; metabolizing volatile toxicants; and generating and transmitting olfactory signals. Common diseases of the URT are rhinitis and sinusitis caused by allergic responses, foreign bodies, viral, fungal and bacterial infection, and neoplasms. Clinical, imaging, and laboratory findings overlap extensively in these conditions, and in most instances identifying the etiology of inflammation requires detailed rhinoscopy, advanced imaging, and collection of cytologic and histologic specimens under general anesthesia. Carefully targeted endoscopic brushings and needle aspirates may identify specific infectious agents and morphologically abnormal cells, while nasal flushes and swabs typically yield only superficial organisms and cells.
In this chapter, the cutaneous metastases of non-primary skin neoplasms, namely those originating from tumors of the internal organs, are discussed. Skin metastases of internal malignancies are, with some exceptions, very rare and only sporadic cases of metastases from gastric, intestinal, prostatic and bronchial carcinomas, from testicular seminoma and from some sarcomas such as haemangiosarcomas and osteosarcomas, have been reported in the veterinary literature. The spread of neoplastic cells occurs mainly via the bloodstream, and therefore, metastases can develop on any part of the skin. The most frequently observed cutaneous metastases are those linked to the bronchogenic carcinoma in cats, which characterise the so-called lung–digit syndrome. In this neoplastic disease, metastases are multicentric and mostly localised to the digits and muscles. Although mammary tissue is cutaneous adnexa, because of the importance and the enormity of the topic, mammary cancers are generally dealt with in textbooks exclusively dedicated to this subject. In dogs, as in human beings, a clinical variant of mammary neoplasia called inflammatory mammary carcinoma is well documented. This neoplasia, shows clinical signs very similar to other primary skin cancers or to nodular non-neoplastic skin diseases, and it is characterised by the lymphatic spread of neoplastic cells. For this reason, this variant of mammary carcinoma is discussed in this chapter. The metastasis of round cell tumors, such as mast cell tumours, lymphomas, histiocytic diseases and multiple myeloma, are not included in this chapter. In these haematopoietic tumours, the simultaneous presence of lesions in the internal organs and on the skin is considered a common occurrence. Furthermore, it is not always possible to define when the skin neoplasia is primary or metastatic. The neoplasms included in this group of tumors have been extensively covered in Chap. 4.
A mass of approximately 5 × 5 × 5 cm was located on the bridge of the nose, nasal septum, turbinates, and soft and hard palates of a 1-year-old male terrier dog. The skin over the mass was alopecic and ulcerated. Histopathologically, the tissue sections consisted of sheets of neoplastic cells separated by narrow bands of fibrovascular stroma. The neoplastic cells were round to polyhedral with moderate, eosinophilic cytoplasm, and large clear nuclei. Mitotic figures were frequently observed. Immunohistochemically, the neoplastic cells were diffusely positive for neuron-specific enolase, but no detectable cellular staining was evident for S-100 protein. Regarding the histopathological and immunohistochemical features of the tissue sections, neuroendocrine carcinoma was concluded in this case.
