Abstract 9729: Pulling Out All the Stops (for a Diagnosis): A Case of Progressive Dyspnea

Abstract

A 63-year-old woman with hypertension, diabetes mellitus, severe obesity, obstructive sleep apnea, and history of GATA3+/ER+ breast cancer treated 14 years prior with neoadjuvant anthracycline-based chemotherapy and subsequent lumpectomy, chest radiotherapy, and letrozole presented to the emergency department with three weeks of progressive cough and exertional dyspnea. Physical examination revealed tachypnea, hypoxemia, a prominent P2, and jugular venous distension with a Kussmaul sign. Further investigation showed moderate hemolytic anemia, severe thrombocytopenia, and elevated natriuretic peptides. Electrocardiography revealed normal sinus rhythm, an S1Q3T3 pattern, and diffuse T wave inversions. Computed tomography angiography of the chest was notable for few small pulmonary nodules and diffuse vertebral osteosclerosis, consistent with osteoblastic metastases. Transthoracic echocardiography exhibited a moderately dilated RV with moderate systolic dysfunction, moderate TR, and an estimated RVSP of 79 mm Hg. Lung perfusion scintigraphy disclosed subtle subsegmental defects. Right heart catheterization (RHC) showed elevated right-sided filling pressures and severe precapillary pulmonary hypertension (RA 12 mm Hg, mPAP 51 mm Hg, PCWP 6 mm Hg, and PVR 775 dynes-sec/cm 5 ). There was no discernable shunt. These findings, coupled with the patient’s history, rapidly progressive symptoms, and hematologic derangements, raised suspicion for pulmonary tumor thrombotic microangiopathy (PTTM). A pulmonary capillary wedge blood aspirate was sent for cytology. Her clinical status rapidly worsened despite inhaled pulmonary vasodilators, hemodynamic support, and systemic glucocorticoids, precluding candidacy for empirical chemotherapy. She was transitioned to comfort measures only and suffered a bradycardic PEA arrest on hospital day 8. Autopsy was declined. Cytological analysis of the wedge blood aspirate ultimately revealed clusters of neoplastic GATA3+ cells, consistent with PTTM associated with late recurrence of breast carcinoma. This case highlights the rare instance of PTTM diagnosis aided by wedge cytology, reinforcing the multidimensional role of RHC in this extremely uncommon and devastating clinical entity.