Sinonasal Hamartomas: From Nasal Chondromesenchymal Hamartoma to Respiratory Epithelial Adenomatoid Hamartoma. Report of six Cases and Review of the Literature

Sinonasal hamartomas are uncommon lesions of nasal and sinus cavities. Based on indigenous cellular components and characteristic histologic features, they are further classified into four entities: respiratory epithelial adenomatoid hamartoma (REAH), seromucinous hamartoma (SH), chondro-osseous and respiratory epithelial hamartoma (CORE), and nasal chondromesenchymal hamartoma (NCH). REAH, SH, and CORE are seen in adult patients, while NCH predominantly occurs in newborns and infants. Morphologically REAH and SH are composed of respiratory epithelium and seromucinous glands, CORE is related to REAH but with additional feature of chondroid and/or osseous tissue, and NCH is composed of chondroid and stromal elements but devoid of epithelial component. All four lesions can present as sinonasal mass lesions and with associated obstructive symptoms. Given the rarity of these lesions, diagnosis can be challenging, especially in unusual clinical scenario. In this study, we report six cases of sinonasal hamartoma, including one case of NCH, one case of CORE, two cases of SH, and two cases of REAH. All cases were from adult patients including four men and two women. We also review the literature of the clinical and pathologic features of these rare lesions.

Adult nasal chondromesenchymal hamartoma: a rare and benign tumour with aggressive malignant transformation

Nasal chondromesenchymal hamartoma (NCMH) is an extremely rare benign tumour of the nasal cavity predominantly described in infants. We report a case involving a 48-year-old woman who had been diagnosed with NCMH a year earlier and now re-presented with a short history of progressive nasal blockage, recurrent epistaxis and orbital apex syndrome. Histopathology was suggestive of malignant transformation into sinonasal sarcoma. However, following multidisciplinary team (MDT) discussions, including second and third opinions from external departments, the histological diagnosis was revised to ‘NCMH with bizarre stromal cells’. Despite this, the lesion demonstrated malignant features of rapid, invasive growth and was treated with palliative radiotherapy. The patient later developed radiological evidence of lung and liver metastases with subsequent pulmonary emboli. Shortly after this, she passed away. This case is unique in its diagnostic challenge, with ambiguous histopathological findings, and highlights the importance of an MDT approach when managing complex sinonasal tumours.

Nasal overshoot: Probably a new entity

Background: Congenital masses of the nasal tip are extremely rare. Differential diagnoses include nasal-tip teratoma, nasal chondromesenchymal hamartoma (NCMH), and heterotopic nasal glioma. Herein, the case of a newborn is reported that does not match with any of these differential diagnoses. Case presentation: A newborn male presented with a congenital pedunculated mass arising from the nasal columella. The mass was symmetrically bilobed which is very unusual for any hamartomatous or neoplastic lesions. Histologically, it was composed of cartilage and ciliated epithelium. Conclusion: Based on the uniqueness of the case it is hypothesized that the lesion could be an embryological error of frontonasal process overshoot defying, hitherto unknown, controlling mechanism. More research is needed to know how the morphometric proportion of the human body is determined by Nature.

Non-resolving acute sinusitis due to nasal hamartoma: a case report

The paranasal sinuses are closely related to vital structures, and therefore, rhinosinusitis may lead to various dangerous complications. Nasal chondromesenchymal hamartoma is a rare benign lesion of the sinonasal tract in children and adolescents. We report the case of a 15-year-old patient with antibiotic-refractory acute sinusitis in whom a nasal tumor was identified and histopathologically diagnosed as a hamartoma. Therefore, the tumor was removed surgically to alleviate the patient’s symptoms. This case highlights the necessity of investigating the underlying cause if conventional treatment fails to resolve a mild disease like acute sinusitis. To the best of our knowledge, this is the first reported case of a chondro-osseous respiratory epithelial adenomatoid hamartoma presenting with acute sinusitis.