Pulmonary Tumor Thrombotic Microangiopathy Caused by a Parotid Tumor: Early Antemortem Diagnosis and Long-term Survival

Abstract

Pulmonary tumor thrombotic microangiopathy (PTTM) is a high-mortality disease that is difficult to diagnose clinically. Our patient was an 80-year-old woman who came to us due to symptoms of increasing dyspnea. A clinical evaluation showed that she had hypoxemia and pulmonary arterial hypertension without any abnormalities in the major pulmonary arteries, bronchi, or alveoli. A lung perfusion scan showed multiple wedge-shaped perfusion defects. Further examination revealed adenocarcinoma in her right parotid gland with metastasis to the submandibular lymph nodes. We diagnosed her to have PTTM caused by a parotid tumor. The patient survived for 11 months with chemotherapy. An early antemortem diagnosis by minimally invasive examinations will help PTTM patients to survive longer.

The pathological challenge of establishing a precise diagnosis for pulmonary tumour thrombotic microangiopathy: identification of new diagnostic criteria

“…These are novel findings that support the diagnosis of this PTTM, as well as a deeper understanding of its morphology. While previous reports have also mentioned arteriolar involvement at various sizes, we observed a predominance of arterioles smaller than 150 μm in diameter. Based on this, four cases in the suspicious PTTM group were identified as not being belonging to this group, but were cases with incidental pulmonary tumour emboli coexistent with lymphangitic carcinomatosis causing respiratory symptoms.…”

“…Although PTTM has been mainly discovered by autopsy, it is becoming increasingly well known by physicians . Several authors have reported on the efficacy of multimodal therapy, and, consequently, the importance of an antemortem diagnosis is growing in order to temper this agonising disease.…”

“…Although PTTM has been mainly discovered by autopsy, it is becoming increasingly well known by physicians . Several authors have reported on the efficacy of multimodal therapy, and, consequently, the importance of an antemortem diagnosis is growing in order to temper this agonising disease. While the major diagnostic feature of PTTM is the coexistence of progressive PH and malignancy, some authors attempted to obtain definitive diagnosis with lung biopsy .…”

Case Report: Pulmonary Tumor Thrombotic Microangiopathy in a Cervical Cancer Patient

“…CT findings for PTTM have ground glass centrilobular micronodules, thickening of the intra-and interlobular septa, and a tree-in-bud pattern, which may represent fibrocellular in- timal proliferation of the small pulmonary arteries, but may also be found in other lung diseases, such as infectious bronchiolitis [13,14] . In some previously reported cases, PTTM was suspected antemortem from the findings of an elevated right ventricular systolic pressure in echocardiography, no thrombi in CT pulmonary angiography or contrast-enhanced CT, and diffuse peripheral perfusion defects in pulmonary perfusion scintigraphy [15] . For a pathological diagnosis of PTTM, pulmonary wedge aspiration cytology [16,17] , transbronchial biopsy [8,18] , CT-guided needle biopsy [2] , and video-assisted thoracic surgery [10] have been reported to be useful.…”

Insights into etiological factors of pulmonary hypertension in cancer patients

“…Most cases are discovered at biopsy since there are no radiological features specific to PTTM, CT scan may be normal or shows dilated pulmonary arteries, wedge-shaped opacities peripherally, thickened interlobular septa or Tree-in-bud sign (centrilobular nodules with linear opacities) [27]. Perfusion studies may demonstrate defects and pathological studies with cytology and biopsy percutaneously or surgically may help in some cases [28]. Apart from supportive treatment and chemotherapy for the underlying malignancy, no specific treatments are available to withhold this fatal complication with most patients are dying shortly after diagnosis [29].…”