- Slides: 19
Radiological Category: Thoracic Principal Modality (1): X-RAY Principal Modality (2): CT/HRCT Case Report # 805 Submitted by: Navid Zaer M. D. Faculty reviewer: Emma C. Ferguson, M. D. The University of Texas Medical School at Houston Date accepted: 8 March, 2011
Case History 49 -year-old Vietnamese woman presented to the hospital with a 4 week history of worsening productive cough and chest pain. PMH: GERD, Anemia. PSH: Noncontributory. FH: Noncontributory The patient has failed a course of antibiotics and has become very fatigued. [Additional history withheld. ]
Radiological Presentations: Chest X-ray Initial radiograph
Radiological Presentations: Chest X-ray 4 week follow up radiograph after antibiotics
Radiological Presentations: Chest CT
Radiological Presentations: Chest HRCT
Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Organizing Pneumonia • Septic Emboli • Atypical Infection • Metastatic Disease
Radiological Presentations: Chest X-ray Combination of interstitial and patchy airspace opacities with lower lung predominance. Subtle ring shaped density in right mid-lung (arrow). Small bilateral pleural effusions.
Radiological Presentations: Chest X-ray Interval progression of patchy airspace opacities. Conspicuous ring shaped lesions in right mid-lung and right upper lobe.
Radiological Presentations: Chest CT Numerous ring shaped consolidative lesions with internal ground glass attenuation. Smooth septal and bronchovascular bundle thickening.
Findings and Differentials Findings: The chest radiographs demonstrate progressive worsening of bilateral interstitial and patchy airspace opacities. Ring shaped lesions are seen in the right mid-lung and right upper lobe. Chest CT/HRCT show numerous consolidative ring lesions with internal ground glass attenuation. Diffuse smooth septal and bronchovascular bundle thickening is noted. No distinct masses or nodules are seen. Not seen on these images is a pericardial effusion. Differentials: • Organizing Pneumonia • Septic Emboli • Atypical Infection • Metastatic Disease
DIFFERENTIAL ORGANIZING PNEUMONIA: This inflammatory disease is a good differential as it often presents with variable flu-like symptoms and can be associated with weight loss. Approximately 20% of cases present with CT findings of the distinctive “reversed halo sign” – central ground glass opacification surrounded by a ring of consolidation - which is present in our patient. Additionally, this disease may present in a variety of patterns including multiple subpleural/peribronchial opacities, solitary alveolar opacities, perilobular, and reticular interstitial distributions. Pathologic evaluation demonstrates polypoid granulation tissue in bronchovascular lumen and alveolar ducts associated with variable interstitial and airspace infiltration by mononuclear cells and foamy macrophages.
DIFFERENTIAL SEPTIC EMBOLISM: Septic emboli would be an appropriate differential in our case based on symptomatic presentation. Radiography often demonstrates 1 -3 cm nodular densities with variable cavitation (“target sign”) which can mimic the “reversed halo sign” seen on x-ray in this instance. When infected embolic material seeds into the lungs due to foreign bodies or infective endocarditis, the primary manifestation on CT is multiple nodules with varying degrees of cavitation, peripheral wedge-shaped opacities, and pleural effusions. Cavitation is a central feature in this entity which does not correlate well with our case.
DIFFERENTIAL ATYPICAL INFECTION: Certain pulmonary infections demonstrate CT findings beyond the expected manifestations of common viral or bacterial pneumonias. Psittacosis (bacterial): This zoonotic infection also known as “parrot fever” presents with cough and fatigue and has been documented as presenting with the “reversed halo sign” in addition to scattered alveolar opacities. Paracoccidioidomycosis (fungal): This systemic mycosis presents with cough, weight loss and often demonstrates a non-resolving lobar pneumonia. Once again, the “reversed halo” presentation has been noted in multiple patients on CT. *The reversed halo sign has recently been noted in PCP pneumonia (viral) as well
CLINICAL COURSE A transbronchial biopsy revealed: (H&E) x 400 – Diffusely infiltrative carcinoma with signet ring features
CLINICAL COURSE & DISCUSSION A subsequent abdominal CT and EGD w/ biopsy demonstrated a 3 cm mass along the greater curvature of the stomach consistent with poorly differentiated adenocarcinoma. A pericardial biopsy was also positive for metastatic disease. METASTATIC DISEASE: Lymphangitic carcinomatosis refers to the diffuse infiltration and obstruction of pulmonary parenchymal and lymphatic channels by tumor. Various neoplasms are implicated but 80% are adenocarcinomas (breast, lung, GI tract). The CT manifestations are varied but can be generally organized into axial (peribronchovascular) or peripheral (interlobular, subpleural) interstitial components. Findings may include irregular/smooth interlobular septal thickening, bronchovascular bundle thickening, and/or prominent polygonal arcades, and are often accompanied by adenopathy and pleural effusions.
DISCUSSION A recent literature review of cardiac tamponade from pericardial metastases originating specifically from gastric cancer discusses the competing theories of hematogenous and lymphatic spread. Of note, 11 out of 12 cases with histopathologic correlation demonstrated massive lymphatic involvement. We postulate that the radiographic pulmonary findings in this patient are quite likely a result of an uncommon variant of lymphangitic carcinomatosis highlighted by irregular thickening of interlobular septa in a reversed halo configuration. It is important to note that metastatic disease also has an important place beside the continually expanding list of infectious and inflammatory disorders exhibiting the “reversed halo” sign which was previously only attributed to organizing pneumonia.
Diagnosis Metastatic Primary Gastric Adenocarcinoma – “Reversed Halo” Variant.
References Kim SJ, Lee KS, Ryu YH, et al. Reversed halo sign on high resolution CT of cryptogenic organizing pneumonia: diagnostic implications. AJR Am J Roentgenol. 2003; 180: 1251 -1254. Kobayashi M, Okabayashi T, Okamoto K, et al. Clinicopathological study of cardiac tamponade due to pericardial metastasis originating from gastric cancer. World J Gastroenterology 2005; 11(44): 6899 -6904 Johkoh T, Ikezoe J, Tomiyama N, et al. CT findings in lymphangitic carcinomatosis of the lung: correlation with histologic findings and pulmonary function tests. AJR Am J Roentgenol. 1992; 158: 1217 -1222 Mapel DW, Fei RH, Crowell RE. Adenocarcinoma of the lung presenting as a diffuse interstitial process in a 25 -year-old man. Lung Cancer. Sep 1996; 15(2): 239 -44. Huang RM, Nadich DP, Lubat E et. al. Septic pulmonary emboli: CT-radiographic correlation AJR Am J Roentgenol. 1989; 153(1): 41 -5