A Rare Case of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH): A Case of Indolent Pulmonary Nodules Diagnosed with Robotic-Assisted Navigational Bronchoscopy

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is an atypical pulmonary disorder with limited understanding. Given the rare nature of this disease, it is essential to obtain adequate tissue pathology to confirm the diagnosis. This disease is mainly diagnosed in middle-aged, nonsmoking females, and it is now accepted as a precursor lesion to pulmonary carcinoid tumors. DIPNECH presents with characteristic radiographic and histologic findings, but its diagnosis, management, and prognosis are often underrecognized and poorly understood. Those with symptoms may present with shortness of breath, wheezing, and persistent cough and are often misdiagnosed with reactive airway disease. Pulmonary function testing may reveal airflow obstruction and air trapping. Imaging is characterized by multiple lung nodules, typically less than 5 mm in size, with a background mosaic attenuation on computed tomography imaging. Histologically, DIPNECH can be suspected based on the presence of hyperplastic neuroendocrine cells. DIPNECH is considered a precursor to invasive neuroendocrine tumor, and up to 50% of patients may have a well-differentiated neuroendocrine tumor at the time of presentation. Here, we present the case of a 46-year-old female with a history of ulcerative colitis on mesalamine who presented with a 6-month history of ongoing shortness of breath, chest tightness, wheezing, and cough. She was initially diagnosed with asthma before imaging later revealed as multiple pulmonary nodules with a diffuse mosaic pattern. Using robotic-assisted navigational bronchoscopy, she underwent sampling of a dominant 1.8 cm right middle lobe pulmonary nodule and pathology was consistent with low-grade neuroendocrine tumor.

Rare diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: one case report and literature review

Rare diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) was first diagnosed in the early 1950s, but was not fully recognized and named until 1992. Literatures reported that DIPNECH usual was multiple and diffuse bilateral nodules, rare patients demonstrate the single nodule or ground glass nodule (GGN). We diagnosed one patient because of intermittent dry cough at least one year, Chest computed tomography (CT) found a purity GGN (pGGN) in the anterior segment, right upper lung lobe, and bronchoscopy didn’t have any tumor in the bronchus in 2014. Continue follow-up 4 years, the nodule enlarged and became a mixed GGN (mGGN) in 2018 on chest CT. A diagnostics video-assisted thoracotomy with wedge resection in right upper lung lobe was performed. The pathology revealed that it was filled with neuroendocrine differentiation cells without penetration terminal bronchiole submucosal layer, immunohistochemical (IHC) staining were positive for CD-56, Cg-A, TTF, Syn and ki-67 (about 5%), leading to diagnosis of DIPNECH. A regular review of the chest CT showed no signs of tumor recurrence postoperative more than 1 year every 6 months, and we will continue follow-up. In conclusion, DIPNECH keeps stable evolution over several years, which is misdiagnosed and underdiagnosed usually. Patient who showed GGN on chest CT and had cough, dyspnea, wheezing, less frequently hemoptysis and so on, we should think of DIPNECH. Diagnosis depended on pathology and IHC staining, regular follow-up will lead to patient a long-term survival postoperative.

Coexistence of DIPNECH and carotid body paraganglioma: is it just a coincidence?

SUMMARY

We describe the case of a 56 year-old woman with the almost simultaneous appearance of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) and a carotid body paraganglioma. Of interest, 6 years earlier, the patient underwent total thyroidectomy due to papillary thyroid carcinoma and, in the meantime, she was submitted to mastectomy to treat an invasive ductal carcinoma of the breast. In order to explain these lesions, an extensive genetic study was performed. Results showed positivity for the presence of the tumor suppressor gene PALB2, whose presence had already been detected in a niece with breast cancer. The patient underwent different procedures to treat the lesions and currently she is symptom-free over 2 years of follow-up.

LEARNING POINTS

The presence of two rare neoplasms in a single person should raise the suspicion of a common etiology. To the best of our knowledge, this is the first case that shows the coexistence of DIPNECH and paraganglioma. The contribution of the PALB2 gene in the etiology of these rare neoplasms is a possibility.

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) with liver metastases

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) is a rare pulmonary disorder characterised by classic radiological findings and symptoms of obstructive lung disease. DIPNECH is considered a precursor to carcinoid tumours in the lungs. In this case, we describe a patient with years of unexplained dry cough presenting with 2 weeks of progressive nausea and vomiting, and found to have massive hepatomegaly on examination. By CT-PE, she was diagnosed with DIPNECH, and abdominal MRI revealed metastatic carcinoid tumours. Despite its non-specific presentation, DIPNECH has characteristic radiological findings of mosaic attenuation with numerous pulmonary nodules. DIPNECH requires early identification and close surveillance to prevent progression to carcinoid tumours. Thus, it is critical for frontline providers to consider this diagnosis as part of their differential when other common causes of obstructive lung disease have been ruled out.

A Rare Case of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia

We describe the case of a 53-year-old woman who visited many pneumologists without a diagnosis until finally being diagnosed with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). It is a relatively new disease characterized by neuroendocrine cell hyperplasia in small airways. She has stable DIPNECH and neuroendocrine carcinoma with somatostatin therapy.