Diffuse intrapulmonary malignant mesothelioma presenting with miliary pulmonary nodules: A case report

Abstract

A 67-year-old male with a history of asbestos exposure presented with fever, cough, and dyspnea and was found to have diffuse granular shadowing in both lungs, right pleural effusion, and hilar and mediastinal lymphadenopathy upon chest computed tomography. For definitive diagnosis, a thoracoscopic lung biopsy was performed. Intraoperative findings showed no remarkable macroscopic changes in the visceral and parietal pleura, although a high level of hyaluronic acid in the pleural effusion was noted. Histological findings showed proliferation of atypical cells with round-to-oval nuclei, prominent nucleoli, and eosinophilic cytoplasms. These cells were arranged into sheets or tubules and were located predominantly in the lung parenchyma. Lymphovascular invasion was conspicuous. Immunohistochemically, tumor cells were positive for calretinin, D2-40, and CK5/6, focally positive for Ber-EP4, but negative for WT-1, TTF-1, CEA, and MOC31. Fluorescence in situ hybridization for the tumor suppressor p16 revealed homozygous deletion in the tumor cells. Therefore, we diagnosed the tumor as diffuse intrapulmonary malignant mesothelioma (DIMM). The patient had a poor response to chemotherapy and died 1 year after diagnosis. Although rare, DIMM should be considered when patients present with multiple, tiny intrapulmonary nodules, regardless of macroscopic pleural changes. Furthermore, this is the first report on p16 status in DIMM.

Malignant pleural mesothelioma showing intrapulmonary lepidic spread

“…The term DIMM is generally associated with diffuse intrapulmonary growth mimicking non-neoplastic lung disease with absent or inconspicuous pleural lesions, whereas miliary mesothelioma has been reserved for intrapulmonary miliary metastasis with or without pleural lesions. 5 Therefore, our case was different from both DIMM and miliary mesothelioma and indicated instead another type of intrapulmonary growth.…”

Localized intrapulmonary desmoplastic mesothelioma: A case report

“…Desmoplastic mesothelioma is a relatively rare histological subtype of mesothelioma with sarcomatoid histology (1) arising most frequently in the pleura, peritoneum or pericardium and less frequently in organs such as lung, spleen [4], pancreas [5] and liver [6]. In fact, few cases of intrapulmonary malignant mesothelioma have been described [2,3,7,8] presenting with bilateral miliary pulmonary nodules and diffuse bilateral opacities or characterized by diffuse intrapulmonary growth, among which some cases [7,8] were pathologically con irmed as intrapulmonary metastases from a clinically undetectable pleural mesothelioma, while the others [2,3] were diagnosed as diffuse intrapulmonary malignant mesothelioma. However, we described an unusual presentation of intrapulmonary mesothelioma characterized by a localized mass without pleural lesions.…”

“…histologically adding necrosis, cystoid and mucoid degeneration diffuse distribution, so that enhancement of SFT in arterial phase is not obvious but obvious in the venous phase, which is the characteristic of progressive enhancement. (2) In lammatory myo ibroblastoma of lung: This tumor density was not uniform, so its liquefaction, necrosis, obviously enhancement are common imaging indings.…”

“…Desmoplastic mesothelioma typically represents an extremely rare histological subtype of sarcomatoid malignant mesothelioma that usually presents with a diffuse pattern of growth [1] and is commonly found in the pleura and peritoneum. The case of localized intrapulmonary desmoplastic mesothelioma is especially rare, although few cases of true intraparenchymal mesothelioma arising in lung have been described [2,3]. It is dif icult to diagnose these tumors clinically and radiologically, and they can inally be con irmed through pathological examination with immunohistochemistry.…”

Mesotelioma Intraparenquimatoso Difuso: Uma Apresentação Rara

“…A positividade para calretinina, citoqueratina 5 (CK5) e para a proteína do tumor de Wilms (WT1), assim como a negatividade para o fator de transcrição da tiróide (TTF1) e para o anticorpo monoclonal contra o antigénio epitelial BerEP4, sugerem o diagnóstico de mesotelioma. 8,9 Revista Científica da Ordem dos Médicos www.actamedicaportuguesa.com A coloração hematoxilina-eosina permite distinguir os quatro principais subtipos histológicos: epitelial, sarcomatoso, bifásico ou misto. 10 O subtipo histológico é um fator prognóstico importante, estando o mesotelioma sarcomatoso associado a um pior prognóstico e o mesotelioma epitelial a um melhor prognóstico.…”