The exophytic masses are usually smooth, dark brown, and lobulated with extensive mucosal ulceration. The average size of the tumors is 2 cm with lesions as small as 0.6 cm reported. In the oral cavity, the growth pattern is somewhat more variable with 50–60% of tumors being exophytic. The average size of laryngeal tumors is approximately 2 cm, but lesions as small as 2 mm have been reported. Greater than 90% of laryngeal and pharyngeal tumors present as polypoid and exophytic masses projecting into the lumen. Ī unique clinical and pathologic feature of SpCC is its macroscopic growth pattern. Tumors of the oral cavity and oropharynx typically present with just the complaint of a mass or with swelling, pain, a non-healing ulcer, dysphagia, or bleeding. Tumors of the larynx present with rather typical symptoms such as hoarseness, voice change, dyspnea, stridor, and cough. Of note, none of the cases of SpCC arose less than 1 year after radiation. This compares with a rate of only 1% or less for conventional squamous cell carcinoma. Combining five major SpCC clinicopathologic studies, 18% of the 326 cases occurred in a previously irradiated field at an average of 7 years and as late as 16 years later. A significant minority of patients have a history of previous radiation to the originating site. Less common sites are the hypopharynx, oropharynx, sinuses, and nasal cavity. The larynx, particularly the glottis, is the most common primary site followed by the oral cavity, specifically the tongue, floor of mouth, and gingivae. SpCC has the same demographics as conventional squamous cell carcinoma, occurring primarily in the fifth and sixth decades, being strongly associated with smoking and drinking, and showing a strong male preponderance. However, as many as one-third are monophasic spindled or pleomorphic tumors making the diagnosis of carcinoma more difficult. In other words, they are composed of both a conventional squamous cell carcinoma and a spindle cell or pleomorphic component. Over time, numerous studies analyzing the morphologic, immunohistochemical, ultrastructural, and molecular features of SpCC have shown epithelial characteristics in the spindle cell population as well as marked genetic similarity between the spindled and squamous portions of biphasic tumors, clearly indicating that the spindle cell component represents divergent differentiation by what is a true carcinoma. Many different theories to explain the morphology were put forward in the past, including divergent differentiation of carcinoma cells, so-called “collision” tumors where there are two separate neoplastic clones combined in the same lesion, and the concept that squamous carcinoma “drives” the proliferation of a pseudosarcomatous stromal response. For years, the true pathophysiology of this spindled component was debated, leading to numerous alternate terms, including carcinosarcoma, pseudosarcoma, pleomorphic carcinoma, and metaplastic carcinoma, among others. SpCC is a variant of squamous cell carcinoma which has spindled or pleomorphic tumor cells which simulate a true sarcoma but are epithelial in nature. Spindle cell carcinoma how to#Keeping this in mind, this review will cover SpCC of the UADT, drawing particularly from five main clinicopathologic studies encompassing 326 cases, review several selected non-neoplastic and benign/low grade lesions that can mimic it, and finally discuss how to differentiate SpCC from them. While it is the most common malignant lesion to present here, this certainly does not mean that what is sitting on your microscope stage tomorrow morning is not a rare mucosal presentation of one of these other lesions. This is what makes SpCC one of the most interesting and challenging of all head and neck tumors. The spindle cell or sarcomatoid component of this tumor can mimic numerous other reactive, benign, and malignant lesions (Table 1). The most common spindle cell lesion presenting along the UADT mucosa is spindle cell carcinoma (SpCC), which has many unique and challenging clinical and pathologic features. Spindle cell lesions can occur in head and neck skin, in the soft tissues of the scalp, orbit, and neck, and along the upper aerodigestive tract (UADT) mucosa. Some are malignant while many others are benign or simply reactive in nature. Spindle cell lesions of the head and neck are quite diverse with great clinical and biological heterogeneity.
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