April 2023 Imaging Case of the Month: Large Impact from a Small Lesion

Michael B. Gotway MD

Department of Radiology

Mayo Clinic, Arizona

Phoenix, Arizona USA

History of Present Illness: A 65-year-old woman with a history of diabetes mellitus complained of worsening fatigue with a 20 lbs. weight gain over the last year as well as shortness of breath. The patient also complained of bruising without recalling specific injury and complained her complexion had changed recently, becoming “ruddier”, accompanied by increasing growth of facial hair. Her past medical history was remarkable for hypertension, including a previous hospitalization for a hypertensive emergency. The patient’s diabetes had become more difficult to control in recent months, with labile blood glucose levels requiring escalating insulin doses. The patient denied recent changes in sleep, worsening anxiety or depression, or changes in mood.

PMH, SH, FH: The patient’s past medical history was also notable for diastolic dysfunction and hyperlipidemia, and she required oxygen use at night. Her past surgical history was significant for a previous hysterectomy and a knee arthroplasty. Her family history was unremarkable.

Medications: Her medications included insulin, pravastatin, lisinopril, metformin, aspirin, furosemide, felodipine, citalopram, and potassium supplementation.

Physical Examination: The patient’s physical examination showed her to be afebrile with pulse rate and blood pressure within the normal range at 128/75 mmHg. She was obese (113 kg) and her facial complexion was indeed ruddy with a rounded appearance. The patient’s skin appeared somewhat thin and several bruises were noted over her extremities. Her lungs were clear and her cardiovascular examination

was normal.

Laboratory Evaluation:  A complete blood count showed normal findings. The patient’s plasma glucose was elevated at 171 mg/dL (normal, 65-95 mg/dL) Her hemoglobin A1c was 9.4% (normal, 4-5.6%). The white blood cell count was normal with no left shift and her liver function studies were entirely normal. Serum chemistries were completely within normal limits aside from a borderline elevated blood urea nitrogen level of 20 mg/dL (normal, 6-20 mg/dL) serum creatinine was normal.

Radiologic Evaluation: Frontal chest radiography (Figure 1) was performed.

Figure 1. Frontal chest radiography.

Which of the following statements regarding this chest radiograph is accurate? (Click on the correct answer to be directed to the next page)

1. Frontal chest radiography shows normal findings
2. Frontal chest radiography shows cardiomegaly
3. Frontal chest radiography shows mediastinal lymphadenopathy
4. Frontal chest radiography shows pleural effusion
5. Frontal chest radiography shows several nodules

Cite as: Gotway MB. April 2023 Imaging Case of the Month: Large Impact from a Small Lesion. Southwest J Pulm Crit Care Sleep. 2023;26(4):48-55. doi: https://doi.org/10.13175/swjpccs014-23 PDF

March 2022 Medical Image of the Month: Pulmonary Nodules in the Setting of Diffuse Idiopathic Pulmonary NeuroEndocrine Cell Hyperplasia (DIPNECH)

Figure 1. Unenhanced chest CT images in the axial plane show solid, non-calcified and well-circumscribed nodules in the right upper lobe (RUL) (A) and lingula (B).  The RUL nodule is FDG-avid on axial fused FDG PET-CT image (C) whereas the lingular nodule is not (D).

Figure 2. Unenhanced chest CT images in the axial plane reconstructed with maximum intensity projection (MIP, A) and minimum intensity projection (MinIP, B) techniques show multiple scattered solid pulmonary nodules (arrows) and pulmonary mosaicism consistent with air-trapping (circled). Axial fused images from a ⁶⁸GA-DOTATATE PET-CT demonstrate some activity in the RUL nodule (C) and more prominent uptake in the lingular nodule (D).

Figure 3.  Hematoxylin and Eosin stained low-power pathological image (A) demonstrates the lingular carcinoid tumor (*) as well as several carcinoid tumorlets (arrows) in the adjacent lung. A separate specimen of lung stained with synaptophysin demonstrates multiple tumorlets in the small sample. When taken in conjunction with imaging findings, pathology is in-keeping with a diagnosis of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH).

A 62-year-old woman presented to an outside hospital with chronic cough, prompting a chest x-ray (CXR). Findings further prompted unenhanced chest CT to evaluate possible pulmonary nodules. The CT demonstrated multiple scattered, solid and centrilobular pulmonary nodules, most of which were small but there were two >1 cm nodules, one in the right upper lobe (RUL) and a second in the lingula (Figure 1A,B). A subsequent FDG PET-CT was performed demonstrating increased metabolic activity in the RUL nodule with no activity in the lingular nodule (Figure 1C,D). Biopsy of the RUL nodule was consistent with a carcinoid. At this point the patient was referred to our center for further management. A repeat chest CT failed to demonstrate any significant change in the nodules. MIP and MinIP reconstructions from that examination demonstrate multiple small, solid pulmonary nodules (arrows) (Figure 2A), many of which were associated with air-trapping resulting in pulmonary mosaicism (circled) (Figure 2B). A ⁶⁸GA-DOTATATE PET-CT was performed, the results of which provide stark contrast to the FDG-PET in that the RUL nodule demonstrated modest uptake (Figure 2C), whereas the lingular nodule showed very prominent update (Figure 2D). The lingular nodule was resected, H & E-stained pathology image (Figure 3A) demonstrated a typical carcinoid (*) with multiple carcinoid tumorlets in the surgical specimen (arrows). A separate specimen stained with synaptophysin demonstrates multiple neuroendocrine tumorlets. Pathological findings, in conjunction with patient demographics and imaging findings, were consistent with Diffuse Idiopathic Pulmonary NeuroEndocrine Cell Hyperplasia (DIPNECH).

DIPNECH is recognized as a pre-neoplastic lesion in the 2015 WHO classification of lung tumors (1). There is neuroendocrine cell proliferation within the small bronchi and bronchioles which may progress beyond the basement membrane, forming carcinoid tumorlets and in some cases, eventually carcinoid tumors.  These airway-centered nodules cause obstruction.  In addition, there is often an association between DIPNECH and constrictive bronchiolitis, which causes further airway obstruction (2).  The vast majority of patients are women in their 50s-70s and most patients are symptomatic with the most common presenting symptoms being chronic cough and dyspnea (3,4).  Many of these patients are often mis-diagnosed with asthma initially (4).  The imaging findings of DIPNECH on CT are not specific but can be pathognomonic in some cases.  There are almost always innumerable small solid (and sometimes ground glass) centrilobular nodules and nodular bronchial thickening with associated pulmonary mosaicism related to air trapping.  Nodules are either stable or very slowly growing over years with the largest nodules usually being biopsied or resected and yielding typical carcinoid on pathology (4).  A relatively new nuclear medicine imaging study, 68Ga-DOTATATE PET-CT, shows promise as a higher resolution and more sensitive examination for detection of neuroendocrine tumors (relative to octreotide scans), including pulmonary carcinoid tumors in the setting of DIPNECH (5,6).

Clinton Jokerst MD¹, Henry Tazelaar², Carlos Rojas MD¹, Prasad Panse MD¹, Kris Cummings MD¹, Eric Jensen MD¹ and Michael Gotway MD¹

Departments of Radiology¹ and Pathology²

Mayo Clinic Arizona, Scottsdale, AZ USA

References

1. Gosney JR, Austin JHM, Jett J, et al. Diffuse pulmonary neuroendocrine cell hyperplasia. In: Travis WD, Brambilla E, Burke AP, et al., eds. WHO classification of tumours of the lung, pleura, thymus and heart. Lyon, IARC Press, 2015; pp. 78-79.
2. Samhouri BF, Azadeh N, Halfdanarson TR, Yi ES, Ryu JH. Constrictive bronchiolitis in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. ERJ Open Res. 2020 Nov 16;6(4):00527-2020. [CrossRef] [PubMed]
3. Rossi G, Cavazza A, Spagnolo P, Sverzellati N, Longo L, Jukna A, Montanari G, Carbonelli C, Vincenzi G, Bogina G, Franco R, Tiseo M, Cottin V, Colby TV. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia syndrome. Eur Respir J. 2016 Jun;47(6):1829-41. [CrossRef] [PubMed]
4. Little BP, Junn JC, Zheng KS, Sanchez FW, Henry TS, Veeraraghavan S, Berkowitz EA. Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia: Imaging and Clinical Features of a Frequently Delayed Diagnosis. AJR Am J Roentgenol. 2020 Dec;215(6):1312-1320. [CrossRef] [PubMed]
5. Deppen SA, Blume J, Bobbey AJ, Shah C, Graham MM, Lee P, Delbeke D, Walker RC. 68Ga-DOTATATE Compared with 111In-DTPA-Octreotide and Conventional Imaging for Pulmonary and Gastroenteropancreatic Neuroendocrine Tumors: A Systematic Review and Meta-Analysis. J Nucl Med. 2016 Jun;57(6):872-8. [CrossRef] [PubMed]
6. Fraum TJ, Ritter JH, Chen DL. Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia on Somatostatin Receptor Imaging. Am J Respir Crit Care Med. 2018 Nov 1;198(9):1223-1225. [CrossRef] [PubMed]

Cite as: Jokerst C, Tazelaar H, Rojas C, Panse P, Cummings K, Jensen E, Gotway M. March 2022 Medical Image of the Month: Pulmonary Nodules in the Setting of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH). Southwest J Pulm Crit Care Sleep;2022:40-42. doi: https://doi.org/10.13175/swjpccs010-22 PDF

Medical Image of the Week: Carcinoid at the Carina

Figure 1. Flow-volume loop showing flattening of expiratory loop suggesting variable intra-thoracic obstruction.

Figure 2. CT of the chest showing pedunculated tracheal lesion at the level of main carina.

Figure 3. Bronchoscopic view of endobronchial tumor before (Panel A) and after removal (Panel B).

A 74-year-old woman with history of 30 pack-year smoking, allergic rhinitis and asthma presented to pulmonary clinic with cough and dyspnea on exertion. She was placed on inhaled corticosteroids and long-acting beta-agonist. Pulmonary function test showed moderate obstructive ventilator defect and flow volume loop suggested variable intra-thoracic obstruction (Figure 1). In the meantime, she was hospitalized with complaint of dyspnea and possible COPD exacerbation. Het CT chest revealed an endobronchial 12 mm pedunculated lesion at anterior aspect of main carina (Figure 2). She underwent flexible bronchoscopy and lesion was removed using electro-surgical snare and cryoprobe (Figure 3). Her symptoms improved post-procedure. Pathologic examination of lesion revealed a carcinoid tumor.

Endobronchial tumors are masses confined within the bronchus, and may be associated with atelectasis or pneumonia of the distal parenchyma. These tracheobronchial tumors are classified as malignant or benign. Malignant tumors arising from surface epithelium include squamous cell carcinoma and neuro-endocrine tumors; and those arising from mesenchyme include sarcoma and malignant lymphoma. On the other hand, benign tumors arising from surface epithelium include squamous cell papilloma and mucus gland adenoma; and those arising from mesenchyme include hamartoma, lipoma, fibroma, leiomyoma, and neurogenic tumor. Hamartomas may present as a fatty mass, nodules with calcification, or as soft-tissue-density nodules on CT scans. The lipomas manifested as fat density on CT scans. The other benign tumors were low-attenuating, soft-tissue-density masses without characteristic findings on CT scans.

Tauseef Afaq Siddiqi, MD; Muhammad Alzoubaidi, MD; James Knepler, MD and Kenneth Knox, MD

Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, The University of Arizona, Tucson, AZ

Reference

1. Ko JM, Jung JI, Park SH, Lee KY, Chung MH, Ahn MI, Kim KJ, Choi YW, Hahn ST. Benign tumors of the tracheobronchial tree: CT-pathologic correlation. AJR Am J Roentgenol. 2006;186(5):1304-13. [CrossRef] [PubMed] 

Reference as: Siddiqi TA, lzoubaidi M, Knepler J, Knox KS. Medical image of the week: carcinoid at the carina. Southwest J Pulm Crit Care. 2015;10(6):341-2. doi: http://dx.doi.org/10.13175/swjpcc052-15 PDF