Occupational and Environmental Health NetWork Puzzler
Case Puzzler |
03.30.10
Clinical presentation
A 70-year-old woman complained of urinary incontinence precipitated by coughing and sneezing. Her only other active medical problems were hypertension and osteoarthritis. She exercised regularly, typically cycling 16 miles daily.
Medical history: unremarkable
Surgical history: bilateral hip replacement
Social history
Tobacco history: 20 pack-years; quit 20 years ago
Occupational history: Retired office clerk. No history of occupational exposure to vapors, gases, dusts, fibers, or fumes.
Family history Her father died of cancer of unknown primary site. Her mother died of chronic kidney disease. Two brothers and one sister are alive and well. Her four children are alive and well. The patient’s father worked in a dusty environment.
Current medications: hydrochlorothiazide, 25 mg daily, and lisinopril, 10 mg daily
Physical examination: normal
Allergies: none
Laboratory data
Urinalysis: microscopic hematuria
Urine cytology: negative result
IV pyelogram: normal result
Renal ultrasound: normal result
Cystoscopy: normal result
Images
An abdominal CT scan was obtained and is shown in Figure 1.
Figure 1. Abdominal CT scan showing a lower cut of the thorax.
Which of the following is seen in Figure 1?
Pleural effusion, visceral and parietal pleural plaque-like density and enhancement
Pleural effusion, osteolytic vertebral lesion
Pleural effusion, para-aortic lymphadenopathy
Pleural effusion, diffuse hepatic and splenic lesions
Correct answer: A. Pleural effusion, visceral and parietal pleural plaque-like density and enhancement
This CT axial section at the level of the lower thoracic cavity shows a left-sided pleural effusion that layers freely, pleural enhancement, and pleural-based plaque-like densities. The vertebra, liver, spleen, and lymph nodes are normal.
A CT of the thorax was obtained and is shown in Figure 2.
The pleural fluid should be tapped in an attempt to establish a diagnosis (eg, specific infection or malignancy) or to narrow the differential diagnosis (eg, exudative vs transudative process). In this healthy and fit patient, PFTs are unlikely to be helpful. The CT findings suggest the diagnostic yield of sputum cytology or bronchoscopy would be very low. Watchful waiting with a follow-up imaging study to assess for interval change is reasonable, if the patient declines thoracentesis.
A thoracentesis was performed. Pleural fluid analysis showed a WBC count of 1,900/μL (63% monocytes/histiocytes, 35% lymphocytes, and 2% mesothelial cells) and a RBC count of 83/μL. Pleural fluid glucose level was 86 mg/dL. Pleural fluid total protein level was 42 gm/dL, consistent with an exudative effusion. Pleural fluid cytologic findings showed atypical cells suggestive of, but not diagnostic of, a malignancy.
The patient then underwent video-assisted thoracoscopic surgery, which showed diffuse pleural nodules and plaques. Two pleural biopsies were obtained. Histopathologic findings included stroma with dense collagen bands infiltrated by a homogeneous noncohesive population of plump, round epitheloid cells with pink cytoplasm and round regular nuclei. Upon staining, this population showed a strongly positive result for calretinin and negative result for TTF1, CEA, and CD15. Extensive invasion into the adjacent pulmonary parenchyma was noted.
Although this patient’s slides were unavailable, we have included a pathologic representation of the same disease in the figure below.
What is your diagnosis?
Submitted by:
Harman S. Paintal, MBBS
US Department of Veterans Affairs
Palo Alto Health Care System Medical Service
Pulmonary Section
Stanford University School of Medicine
Richard Evans, MD, MPH, FCCP
University of Rochester School of Medicine and Dentistry
Kristin Jensen, MD
US Department of Veterans Affairs
Palo Alto Health Care System Pathology Service
Stanford University School of Medicine
John Drace, MD
US Department of Veterans Affairss
Palo Alto Health Care System Radiology Service
Stanford University School of Medicine
Ware G. Kuschner, MD, FCCP
Palo Alto Health Care System Medical Service
Pulmonary Section
Stanford University School of Medicine
Case Puzzlers are a brief clinical vignette on various educational topics. Developed by members of the American College of Chest Physicians' NetWorks, it provides you an opportunity to sharpen your skills.
