Pulmonary oncocytoma: report of a case in conjunction with an immunohistochemical and ultrastructural study

Bronchial oncocytic carcinoma in an adult: a case report and literature review

BACKGROUND

Lung salivary-type tumors originating from bronchial submucosal glands are rare, only four types of salivary gland-type tumors are listed in 2015 WHO classification of lung tumors. Here, we report a rare case of oncocytic carcinoma (OC) in the right main bronchus.

CASE PRESENTATION

A 34-year-old man presented to our hospital with a two-month history of recurrent hemoptysis and with one month of inspiratory dyspnea. Pulmonary function tests showed mild restrictive ventilatory dysfunction and severe diffusion dysfunction. Furthermore, the flow volume loop showed a variable extra-thoracic obstruction. Computed tomography (CT) of the chest revealed that a polypiform nodule of 13 mm in diameter was at the proximal right main bronchus. Testing for purified protein derivative was positive (category 2). The nodule was resected under bronchoscopy. The bronchial aspirate was negative for mycobacterium tuberculosis and tumor cells. The biopsy sample showed a solid and acinar predominant pattern with abundant eosinophilic cytoplasm. The bronchial mucosa was destroyed and replaced by tumor cells. The loose edematous stromal reaction could be seen in a local area. Immunohistochemically, tumor cells were positive for CK, EMA, Vimentin, CD117, CK7, S100, Mammaglobin and SOX10. Only scattered tumor cells were stained by basal cell markers, including CK5/6, P40 and P63. Electron microscopy revealed numerous swelling mitochondria with lacking mitochondrial cristae in tumor cells. Fluorescence in situ hybridization (FISH) testing for MAML2 and ETV6 rearrangement were negative. Next-generation sequencing analysis of 520 genes in the tissue biopsy specimen showed no somatic mutation. The diagnosis of OC was made. Subsequently, the patient underwent a right upper lobectomy with sleeve resection of the main bronchus and lymph dissection. No recurrent evidence was seen during two years of chest CT follow-up.

CONCLUSIONS

To our knowledge, this is the first case of primary OC in the bronchus. This patient has no recurrence during two years of follow-up, indicating that primary OC in the bronchus has the same favorable prognosis as in salivary glands. Moreover, complete excision and thorough sampling to know the invasive growth pattern is important to reach the correct diagnosis.

Primary Pulmonary Salivary Gland-type Tumors: A Review and Update

Pulmonary salivary gland-type tumors (SGT) comprise a very small proportion of primary lung neoplasms. The most common tumors among this group are mucoepidermoid carcinoma and adenoid cystic carcinoma. Contrary to the head and neck region, benign SGT such as pleomorphic adenomas are exceedingly rare in the pulmonary system. More recently, 2 additional SGT, namely hyalinizing clear cell carcinoma and salivary duct-like carcinoma were recognized as primary lung tumors expanding the spectrum of SGT that have been described to originate in the tracheobronchial system. Primary pulmonary SGT must be clinically excluded from metastatic salivary gland neoplasms as their morphology is indistinguishable from that of their salivary gland counterparts. Little is known about the clinical behavior and best treatment approach for these unusual tumors. In this review, we provide a comprehensive summary of primary pulmonary SGT with particular emphasis on morphologic characteristics and latest developments in terms of immunohistochemical and molecular techniques.

Thoracoscopic surgery for pulmonary oncocytoma, an uncommon neoplasm

Oncocytoma is an uncommon neoplasm with a characteristic histologic feature of abundant eosinophilic granular cytoplasm. It almost always occurs in kidney, thyroid, or salivary gland. Pulmonary oncocytoma is a rare pulmonary neoplasm, with fewer than 10 cases reported so far in the available English literature. We encountered one such case that was successfully managed by thoracoscopic lobectomy.

Oncocytic mania: a review of oncocytic lesions throughout the body

Oncocytic lesions are characterized pathologically by an abundance of oncocytes, that is by enlarged, eosinophilic, and finely granular cells enriched in mitochondria. They can arise in numerous organs and tissues, often in endocrine glands, and have been associated with hyperplasia, autoimmunity, and neoplasia. The causes and mechanisms that transform a normal cell into an oncocyte remain to be elucidated. Aim of this article is to review the most common oncocytic lesions, highlighting their key pathological features and clinical significance.

Bronchial oncocytoma

CONTEXT

Oncocytomas are generally small and present slow growth. Finding of the tumor usually occurs incidentally. Their incidence is higher among male patients. Oncocytomas in mucous bronchial glands are extremely rare.

CASE REPORT

A 35-year-old male who presented bronchial oncocytoma. The tumor was found after bronchoscopy that investigated an atelectasis of the upper left lobe. Histological examination with optical microscopy revealed a mature neoplasm formed by ovoid cells with thin, granular, eosinophilic cytoplasm and small nuclei similar to oncocytes. Electron microscopy showed mitochondrial hyperplasia. A three-year follow-up after thoracotomy followed by lobectomy and removal of the bronchial tumor was uneventful.

Endocrinological and pathological entities of the pre-Cushing's syndrome

The purpose of the study was to clarify the disease entity of pre-Cushing's syndrome. The authors report on the pathological findings and contents of various steroids in the adenomas of three cases of pre-Cushing's syndrome. Oncocytes were found in one adenoma and others were pure clear cell dominant adenomas. All the adenomas contained higher concentrations of precursor steroids than those of five cases of Cushing's syndrome. However, the patterns of increased precursors were quite different among the three cases. Pre-Cushing's syndrome appeared to include several different kinds of disease entities.