Statistics show that this clinical manifestation is present in 15% of persons with RP and occurs at some point in 65% of persons with RP.Nasal obstruction is not a common feature. Atrophy may eventually develop secondarily during the disease, this appears gradual and is not easily noticed. This can result in collapse of the nasal septum with saddle-nose deformity, which is painless but irreversible. Respiratory tract
Inflammation occurs in the laryngeal, tracheal and bronchial cartilages. Both of these sites are involved in 10% of persons with RP at presentation and 50% over the course of this autoimmune disease, and is more common among females. The involvement of the laryngotracheobronchial cartilages may be severe and life-threatening; it causes one-third of all deaths among persons with RP. Laryngeal chondritis is manifested as pain above the thyroid gland and, more importantly, as dysphonia with a hoarse voice or transient aphonia. Because this disease is relapsing, recurrent laryngeal inflammation may result in laryngomalacia or permanent laryngeal stenosis with inspiratory dyspnea that may require emergency tracheotomy as a temporary or permanent measure.Tracheobronchial involvement may or may not be accompanied with laryngeal chondritis and is potentially the most severe manifestation of RP.The symptoms consist of dyspnea, wheezing, a nonproductive cough, and recurrent, sometimes severe, lower respiratory tract infections. Obstructive respiratory failure may develop as the result of either permanent tracheal or bronchial narrowing or chondromalacia with expiratory collapse of the tracheobronchial tree. Endoscopy, intubation, or tracheotomy has been shown to hasten death. Ribs
Involvement of the rib cartilages results in costochondritis.
Pathogenesis
Different molecular mechanisms are involved in PRCC development, which further result in distinct histologic features and clinical outcomes.Type 1 PRCC is caused by a genetic mutation or a gain in chromosome 7 where the MET gene is positioned, resulting in the promotion of oncogenic pathways in renal epithelial cells. Typically, the MET gene is upregulated for renal tissue repair and regeneration by encoding the receptor tyrosine kinase c-MET of hepatocyte growth factor. However, activation of the oncogenic pathway in the MET gene will manifest invasion, anti-apoptosis, angiogenesis, and metastasis.Type 2 PRCC is associated with irregularity of several signaling pathways, which includes CDKN2A silencing, mutation in chromatin-modifying genes, and a GpG island methylator phenotype (CIMP). CDKN2A is a tumor suppressor gene, while loss of its expression results in enhanced tumorigenesis and metastasis. Moreover, mutation of gene involved in chromatin remodeling (SETD2, BAP1, or PBRM) may lead to higher rate of TFE3/TFEB fusion. Additionally, CIMP papillary renal cell carcinoma tumors exhibited somatic FH gene mutation, which is closely associated with HLRCC syndrome. Diagnosis
Currently, cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) is known as the best option for diagnosing papillary renal tumors. Computed tomography (CT)
Contrast-enhanced computed tomography (CT) is most commonly used to identify the subtypes of RCC. PRCC can be differentiated from other types of RCC due to its distinguishing features, displaying a small hypovascular renal tumor on T2 weighted images.