Lymphangiomatosis

Clinical History

A 33-year-old woman presented with slowly progressive shortness of breath, cough with abdominal fullness. There was no prior history of surgery. On clinical examination there were features of superior vena cava syndrome with splenomegaly.

Imaging Findings

CECT scan of thorax shows hypodense lesion of fluid attenuation with barely perceptible wall or enhancement filling precarinal, prevascular space, aortopulmonary window, azygoesophageal recess, middle and posterior mediastinum encircling the pulmonary veins, ascending and descending aorta without luminal narrowing, involving pericardium and extending across midline (Fig. 1-3). SVC and azygous vein are dilated (Fig. 1).
The lesion has few thin septae and is filling the lesser sac, hepatogastric ligament, encasing portal vein with similar cystic lesions in splenic parenchyma. Spleen is enlarged with dilated portosplenic axis (Fig. 4).
Coronal CECT images show extensive thoracoabdominal extension of nonenhancing lesion involving multiple compartments and spaces without obvious mass effect over other visceral organs (Fig. 5). Thickening of interlobular septa and peribronchovascular interstitium seen without any ectatic airways, radiolucent cystic areas or air space disease (Fig. 6, 7). Mildly prominent right oblique fissure and focal right lateral pleural thickening was noted (Fig. 8).

Discussion

Lymphangiomas are congenital lesions which occur due to failure of developing lymphatic tissue to establish normal communication with remainder of the draining lymphatic system [1, 4]. Histologically they are of three types: capillary, cavernous and cystic [4]. They are most commonly seen as cervical, axillary masses while mediastinum and retroperitoneum are uncommon locations [4]. Lymphatic disorders of thorax have been classified into four types: lymphangiectasis, localized lymphangioma, diffuse lymphangioma, lymphangioleiomyoma [2].
Diffuse non-localized proliferation of lymphatic spaces with wide spread involvement of multiple anatomical compartments and visceral organs without proliferation of smooth muscles is termed lympahngiomatosis [2]. Mediastinal involvement is common in young adults with coexistence of chylous pleural and pericardial effusions [2].
Variable clinical findings include cough, dyspnoea, dysphagia, superior vena cava syndrome, organomegaly, features related to secondary infection, or may be completely asymptomatic [1]. They may involve peritoneal and retroperitoneal compartments in abdomen [3].
Cross sectional imaging reveals diffuse distribution of the disease. On CECT the lesion appears as an insinuating mass of fluid attenuation without any enhancement or perceptible wall enveloping normal mediastinal structures, peritoneal organs without any obvious mass effect [3]. Elongated nature of the tumour and involvement of multiple compartments in peritoneal cavity or spaces in the mediastinum without any invasiveness support the fact that these are developmental anomalies of dilated lymphatic channels [3]. HRCT may reveal diffuse reticular interstitial lung disease due to proliferation of lymphatics along interlobular septae and bronchovascular interstitium although cystic radiolucent areas are rarely seen because normally arranged smooth muscles line the wall of the lymphatic spaces, unlike that of lymphangioleiomyomatosis [2].
MR imaging depicts anatomic extent of the lesion better than CT, gives information about the nature of the possible fluid content (proteinaceous/haemorrhagic) and helps in detecting recurrences [4]. Sonography is useful in delineating septations, loculations in the lesions and debris in cases of secondary infection [3].
Preoperative exact anatomical extent and location of the lesions needs to be determined for therapeutic approach. Though complete surgical excision is treatment of choice, palliative procedures need to be considered at times owing to the diffuse widespread nature of the disease [2].
Lymphangiomatosis should be considered as an important differential diagnosis in cases of diffuse cystic lesions of the mediastinum not localized to a particular anatomical space, encircling organs without any displacement or invasion [1, 2]. Despite the extensive involvement imaging findings are quite specific when correlated with clinical presentation and help to rule out other differential diagnoses.

Differential Diagnosis List

Final Diagnosis

Lymphangiomatosis

URL:	https://www.eurorad.org/case/11316
DOI:	10.1594/EURORAD/CASE.11316
ISSN:	1563-4086