A 63-year-old woman presented to our pulmonary clinic for evaluation of multiple bilateral pulmonary nodules. She had been recently hospitalized for a transient abdominal illness at an outside hospital, and an abdominal CT at that time detected multiple subcentimeter lesions in the bilateral lower lobes, but was otherwise unremarkable. Her past medical history was notable for hypertension, diabetes, gastroesophageal reflux, thalassemia, and remote and treated pulmonary coccidioidomycosis, which was previously identified by serology without associated x-ray findings at the time of diagnosis. She was a lifelong nonsmoker and did not have any known occupational exposures, but endorsed a passive smoke exposure in her home environment and had a family history of lung cancer.
She had also been seen in our pulmonary clinic eight years prior for incidentally detected bilateral pulmonary nodules. These nodules were initially detected in February 2008 at an outside facility. On our assessment in May 2008, a chest CT without contrast showed findings radiologically consistent with several benign intrapulmonary lymph nodes and subpleural lymph nodes in the posterior portion of both lower lobes. Benign-appearing linear fibrosis was also noted in the right upper lobe apical segment medially and in the inferior lingular segment. In the right upper lobe, this abnormality was possibly associated with an endobronchial lesion (Fig. 1a), although this was not well appreciated at the time of initial evaluation and this was only recognized on subsequent review many years later when she presented again. Follow-up imaging 7 months later in 2008 was unchanged and ultimately these findings were felt to be benign without the need for subsequent imaging.
On our imaging assessment in 2016, a CT scan without contrast demonstrated a dominant slowly growing 14 mm nodule apparently centered along a subsegmental branch of the right apical segmental bronchus (Fig. 1b), in the same area where linear fibrosis was noted in 2008. The nodule appeared to be associated with airway obstruction and mucous plugging. Given the extremely slow interval growth and the fact that the lesion was centered on an airway, a typical carcinoid tumor was suspected. In addition, the patient had increasing mediastinal lymphadenopathy, predominantly in the right paratracheal region. Multiple additional subcentimeter pulmonary nodules were noted, many of which appeared to have a centrilobular distribution. Some of these nodules were stable back to 2008 and some had slightly increased in size. Additionally, there were numerous indeterminate nodules within the lungs bilaterally, as well as some new nodules along the fissures, which were new since December 2008.
Multiple prominent mediastinal lymph nodes were also noted as well as multiple indeterminate nodules along the fissures (Fig. 1c). Accordingly, bronchoscopy was pursued.
At the time of bronchoscopy, using the BCUC180F flexible fiberoptic bronchoscope, an endobronchial lesion was visualized in the right upper lobe, at posterior subsegmental level and aspirated. An endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed using an Olympus EBUS-TBNA needle and sent for routine cytopathologic evaluation from lymph node stations 4R (lower paratracheal), 7 (subcarinal), and 10R (hilar) lymph nodes. The cytology specimen from the endobronchial lesion showed features suspicious for a low-grade spindle cell neoplasm, with small fragments of spindle cells with myxoid changes. The biopsied lymph nodes were negative for malignancy. Fungal and nocardial cultures were negative, as well as PCR testing for coccidioidomycosis. Her PET scan showed multiple hypermetabolic mediastinal and hilar lymph nodes as well as a hypermetabolic submandibular lymph node.
Collectively, this prompted us to pursue right video-assisted thoracoscopy with right upper lobectomy and mediastinal lymph node dissection. She tolerated the procedure well without complications.
Histopathologic evaluation of the lobectomy specimen demonstrated a polypoid and well-circumscribed submucosal proliferation of neoplastic cells projecting into the lumen of a small bronchus (Fig. 2). These tumor cells formed small bilayered glandular structures, cords, and small nests in a background of variably fibrotic and focally myxoid stroma. Cytologically, the neoplastic cells were bland with minimal mitotic activity, and necrosis was absent. Two distinctive components were present, with an epithelioid ductal cell component surrounded by a clear to spindled myoepithelial component. The ductal cell component displayed immunoreactivity for pancytokeratin AE1/AE3, whereas the myoepithelial cell component expressed smooth muscle actin and S-100 protein. Unexpectedly, both components displayed immunoreactivity for TTF-1, but no immunostaining was seen in either component for ALK, desmin, or CD34. These findings did not fulfill criteria for other recognized salivary gland-type neoplasms and were instead most in keeping with the reported features of pneumocytic adenomyoepithelioma.
Interestingly, sections of the lymph nodes showed no evidence of metastasis, but extensive non-necrotizing granulomatous lymphadenitis was identified with morphologic features consistent with sarcoidosis, and Gomori methenamine silver, Ziehl-Neesen acid-fast, and auramine-rhodamine stains were all negative for microorganisms. Sputum cultures grew 1+ normal flora. From the bronchoalveolar lavage, Pneumocystis Smear, Legionella PCR, Legionella Culture, Fungal Smear, Fungal Culture, Nocardia Smear, Coccidioides PCR, and Mycobacterium Culture were all negative. It was felt that her noncaseating granulomatous lymphadenitis likely represented a reactive sarcoidosis, we elected not to treat with steroids. Of the few reported cases of pneumocytic myoepithelioma, associated sarcoidosis has not been reported.
On follow-up imaging 2 months later, her bilateral pulmonary nodules were stable without evidence of interval change and she felt well overall. Pulmonary function tests were also obtained, which were unremarkable.