Pleural Malignant Mesothelioma with Micropapillary Pattern: A Case Report and Literature Review

Case Report

Austin J Lung Cancer Res. 2016; 1(1): 1005.

Pleural Malignant Mesothelioma with Micropapillary Pattern: A Case Report and Literature Review

Yang G¹*, Qin X², Zaheer S³ and Nepomuceno- Perez MC¹

¹Department of Pathology and Laboratory Medicine, Loma Linda University Medical Center, USA

²Department of Internal Medicine, Loma Linda University Medical Center, USA

³Department of Surgery/Cardiothoracic, Loma Linda University Medical Center, USA

*Corresponding author: Yang G, Department of Pathology and Laboratory Medicine, Loma Linda University Medical Center, 11234 Anderson St, Loma Linda, California 92354, USA

Received: November 13, 2015; Accepted: January 13, 2016; Published: February 11, 2016

Abstract

Recent studies show that invasive micropapillary pattern in pleural malignant mesothelioma, characterized by cellular tufts lacking central fibrovascular cores, can predict a more aggressive lymphatic spread, similarly seen in carcinomas in other organs with micropapillary pattern. Here, the authors report a rare case of pleural malignant mesothelioma with micropapillary pattern, widespread lymphovascular invasion, and regional nodal and pulmonary micro metastasis. The authors further describe the main histologic and immunehistochemical features, discuss possible mechanism(s), along with a brief literature review

Keywords: Malignant mesothelioma; Micropapillary; Pleura; Metastasis; Invasion; Immunohistochemistry

Case Presentation

A 56-year-old Hispanic female with uncertain asbestos exposure developed shortness of breath, cough and left chest pain. She was evaluated elsewhere and found to have left pleural effusion. After initial workup was non diagnostic, she underwent left Video Assisted Thoracic Surgery (VATS) and pleural biopsy. The pathology showed mesothelioma and she was referred to our institution for definitive care. Past medical history includes hypertension, diabetes mellitus and hyperlipidemia. Patient has a less than 1 pack year remote smoking history.

On presentation at our institution, she complained of left chest pain with a dry cough. Her physical examination was unremarkable with healing left chest incisions. Staging workup included chest Positron Emission Tomography / Computed Tomography Scan (PET/CT), Magnetic Resonance Imaging (MRI) of the chest, mediastinoscopy and laparoscopy. PET/CT showed hyper metabolic activity in the left pleural space and mild uptake in subcarinal, superior mediastinal and bilateral level IIa cervical lymph nodes (Figures 1&2). Chest (Figure 3) showed circumferential left pleural irregular thickening and loculated pleural fluid but no frank mediastinal, diaphragmatic or chest wall invasion. Mediastinoscopy showed no malignant involvement of #4R, #4L and #7 lymph node stations. Laparoscopy was negative for peritoneal involvement. She was clinical stage II. Results of pulmonary function tests showed FEV1 (Forced Expiratory Volume in 1 second) of 1.72 (68%) and DLCO (carbon monoxide diffusing capacity) of 66%. Her echocardiogram was normal at rest and after stress. She also underwent pulmonary stress test and had excellent VO2 max. Our histopathologic review of left pleural peel from the outside VATS confirmed epithelioid pleural malignant mesothelioma.

After extensive discussions about the risks, benefits and alternatives of different treatment options, she opted for tri-modality therapy. She was taken to the operating room for a left extra pleural pneumonectomy. We preserved the pericardium. The diaphragm was reconstructed with 2mm Gortex mesh. All the previous port sites were resected enbloc with the specimen. A complete Mediastinal lymph node dissection was performed. Her hospital course was unremarkable and she was discharged on the 5th post-operative day. Follow-up in the clinic after 2 weeks was unremarkable. She is scheduled to undergo adjuvant chemotherapy and radiation in the near future.

Gross & Microscopic pathology

The resected specimens consisted of left extra pleural pneumonectomy with diaphragm and chest wall, left 6th rib, level 5 and 7 lymph nodes. Gross examination showed multiple tan-white, firm, peripheral rind-like masses up to 6.5 cm in greatest dimension diffusely involving visceral and parietal pleura (Figure 4), with inferior and medial extension to diaphragmatic and mediastinal surfaces.