Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A. Address correspondence and reprint requests to Lindsay Young, M.D., Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9035, U.S.A.; E-mail: [email protected] The authors declare no conflicts of interest.

BACKGROUND:Paranasal sinus fibro-osseous (FO) lesions represent a heterogeneous group, often sharing overlapping radiographic and pathologic features posing a dilemma in accurate diagnosis. The objective of this study was to correlate preoperative radiologic and postoperative histologic diagnosis to help guide a diagnostic algorithm. METHODS:Retrospective analysis of 60 FO lesions between 1994 and 2010. RESULTS:The mean age was 42.3 years with average follow-up of 12.5 months. The preliminary radiologic diagnosis was osteoma in 22 (36.7%), fibrous dysplasia (FD) in 9 (15%), ossifying fibroma (OF) vs FD in 5 (8.3%), and OF in 3 (5%) cases. The diagnosis was indeterminate in 21 (35%) cases. Management consisted of excision in 29 (48.3%), observation in 17 (28.3%), and biopsy in 14 (23.3%) patients. For patients undergoing resection or biopsy, positive predictive value of preoperative radiology was 100% (10/10) for osteoma, 85.7% (6/7) for FD, and 33.3% (1/3) for OF cases. For the indeterminate lesions, most common pathologic diagnoses for 21 patients included osteoma in 4 (17.4%), arrested pneumatization in 3 (14.3%), OF in 3 (14.3%), and FD in 2 (9.5%). For FD vs OF cases, 3 underwent surgery, revealing osteoma, FD, and OF in 1 patient each. CONCLUSION:In this series, radiologic-histopathologic correlation was high for osteoma and FD and low for OF and OF vs FD. This data suggests that patients with classic radiologic characteristics of osteoma and FD may be observed, unless resection is warranted based on clinical symptomatology. Preoperative diagnosis of OF, OF vs FD, or indeterminate lesions may warrant a biopsy to establish firm diagnosis to guide definitive management, especially if preoperative computed tomography (CT) imaging is concerning for an aggressive FO neoplasm.

With a rat model of vocal fold injury, this study examined the in vivo host response to an acellular xenogeneic scaffold derived from the bovine vocal fold lamina propria, and the potential of the scaffold for constructive tissue remodeling. Bilateral wounds were created in the posterior vocal folds of 20 rats, and bovine acellular scaffolds were implanted into the wounds unilaterally, with the contralateral vocal folds as control. The rats were humanely sacrificed after 3 days, 7 days, 1 month, and 3 months, and the coronal sections of their larynges were examined histologically. Expressions of key matrix proteins including collagen I, collagen III, elastin, fibronectin, hyaluronic acid, and glycosaminoglycans (GAGs) were quantified with digital image analysis. Significant infiltration of host inflammatory cells and host fibroblasts in the scaffold implant was observed in the acute stage of wound repair (3 days and 7 days postsurgery). The mean relative densities of collagen I, collagen III, and GAGs in the implanted vocal folds were significantly higher than those in the control after 3 days, followed by gradual decreases over 3 months. Histological results showed that the scaffolds were apparently degraded by 3 months, with no fibrotic tissue formation or calcification. These preliminary findings suggested that the bovine acellular scaffold could be a potential xenograft for vocal fold regeneration.

A bovine acellular scaffold was found to facilitate tissue remodeling in a rat model of vocal fold injury, whereas hepatocyte growth factor (HGF) has been shown to have an antiscarring effect in the larynx. This study examined the loading and release kinetics of HGF in vitro, and the potential of the acellular scaffold as a timed-release system for the delivery of HGF in vivo. Bilateral wounds were created in the posterior vocal folds of 20 rats, with HGF-loaded acellular scaffolds implanted into the wounds unilaterally, and scaffolds without HGF implanted into the contralateral vocal folds as control. The rats were humanely sacrificed after 3, 7, 30, and 90 days and their larynges were examined histologically and immunohistochemically. Expressions of key matrix proteins in the vocal fold coronal sections were quantified by digital image analysis. Results demonstrated a gradual, sustained release of HGF for at least 7 days in vitro, consistent with the detection of glycosaminoglycans inherent of the scaffold. In rat vocal folds implanted with HGF-loaded scaffolds, apparently fewer inflammatory cells were observed 3 days after surgery when compared to the control. The mean relative densities of collagen III and hyaluronic acid were significantly lower than those of the control 7 days after surgery. Scaffold implants were apparently degraded by 3 months in all animals, with no evidence of fibrosis or calcification. These data suggested that the bovine acellular scaffold could be promising for the exogenous delivery of select growth factors in vivo.

Interdigitating dendritic cell sarcoma (IDCS) is an exceedingly rare neoplasm arising from the antigen-presenting cells of the immune system. We report a case of IDCS occurring in a 69-year-old man who presented to an outside institution with a painless mass in his right parotid gland for several months. He presented to our institution after undergoing a superficial parotidectomy. A diagnosis of undifferentiated neoplasm, favoring poorly differentiated carcinoma, was made at that time. He underwent a total parotidectomy and neck dissection at our institution. Microscopically, the tumor was composed of atypical spindle cells involving the parotid gland and an ipsilateral level III lymph node. Immunophenotypic analysis demonstrated positive staining for S100, fascin, vimentin, and HLA-II. Follicular dendritic cell, lymphoid, epithelial, myoepithelial, and melanoma markers were negative. Taken together, the above features were consistent with IDCS. An IDCS of the parotid gland is extremely rare, with only 2 cases reported in the literature. The unusual location and morphological similarity to follicular dendritic sarcoma and other types of soft tissue sarcomas can be a diagnostic challenge. Awareness of this tumor and the use of appropriate markers are crucial in making the diagnosis. The patient did well postoperatively, and he underwent a complete course of postoperative irradiation to the right parotid and neck.