Subdiaphragmatic Pulmonary Sequestration: A Case Report With Review of the Literature

Abstract

Pulmonary sequestration is defined as a mass of abnormal lung tissue that does not communicate with the tracheobronchial tree through a normally located bronchus. Most authors classify these sequestrations either as extralobar if the mass is covered by its own pleural investment or intralobar if incorporated within the normal lung without a separate pleural membrane. Sequestrations may communicate with the gastrointestinal tract 1 and are also supplied by an anomalous systemic artery. The vast majority of the extralobar lesions are present within the thorax, most frequently between the left lower lobe and the diaphragm and rarely below it. 2 Embryologically, these lesions are best categorized as a form of foregut malformation. 1,3,4 Associated anomalies are seen in ϳ65% of the patients with extralobar sequestrations (ELS) and rarely in patients with intralobar sequestrations. The anomalies usually include diaphragmatic hernias and congenital cystic adenomatoid malformation (CCAM).Bronchogenic cysts, teratomas, neuroblastoma, intestinal duplications cysts, adrenal hemorrhage, and renal dysplasia should be considered among the more common differential diagnoses of subdiaphragmatic lesions in the perinatal period. CLINICAL HISTORYA left suprarenal mass was detected at 22 weeks' gestation during a routine ultrasound (US). A 1.5 ϫ 0.8-cm hyperechoic and cystic lesion was noted to the left of the lumbar spine and superior to the left kidney (Figure 1). No feeding vessel was noted by US, and no hemorrhage was detected by ultrafast fetal magnetic resonance imaging. The clinical differential diagnosis included neuroblastoma and pulmonary sequestration. The postnatal computed tomography scan and US were consistent with an adrenal neuroblastoma. Neonatal urinary vanilylmandelic acid was reported as negative.The left adrenal and the tumor were resected at 40 days after delivery. The specimen weighed 3.56 gm and contained a 2 ϫ 1 ϫ 0.5-cm "fleshy" nodule along the superior and medial aspect of the adrenal gland. Serial longitudinal sections disclosed a well-delineated, solid, tan lesion with a 0.2-cm white-gray collapsed cyst at one of the edges (Figure 2). The adjacent adrenal gland was unremarkable.Touch preparations disclosed many ciliated columnar cells (Figure 3). The nodule was composed of many irregular cystic and tubular structures resembling bronchioles. These structures were lined by a ciliated respiratory epithelium and were surrounded by smooth muscle fibers and islands of cartilage resembling a CCAM type II ( Figure 4). In other areas, the lesion had an alveolar pattern, and the luminal spaces contained proteinaceous fluid with many foamy macrophages. There was an associated mild lymphocytic infiltrate. The adjacent adrenal gland was normal for age. DISCUSSIONELS located in the abdomen are rarely diagnosed before excision. Certain laboratory and imaging pitfalls should be considered to avoid a misdiagnosis. [5][6][7][8][9][10][11][12][13][14][15] For example, vanilylmandelic acid and homovanillic acid may be ne...

Retroperitoneal extralobar pulmonary sequestration mimicking a pheochromocytoma

“…The histological findings in ELS are reported to include dilated bronchial structures lined by ciliated pseudostratified columnar epithelium with underlying fibromuscular tissue, similar to the present case. These bronchial structures can become cystically dilated by mucous secretions, thereby giving the appearance of a multicystic mass 1,3 . Hyaline cartilage plates, alveolar structures and bronchial seromucous glands can also be seen, the latter being found predominantly in this case.…”

Prenatal Detection of an Extra‐Adrenal Neuroblastoma With Hepatic Metastases

“…A broad differential diagnosis for neuroblastoma has been proposed in the literature and includes hemorrhage, 18 subdiaphragmatic extralobar pulmonary sequestration, 19 a multicystic dysplastic kidney, 20 neurogenic cysts, 21 mesoblastic nephroma, 21 Beckwith-Wiedemann syndrome, 22 retroperitoneal teratoma, 23 enteric duplication cysts, 24 liver tumors, and splenic cysts. 25 Prenatal sonograms and magnetic resonance images are useful in the differential diagnosis of a neuroblastoma from a mesoblastic nephroma and other neoplasms occurring in the retroperitoneum.…”

“…With respect to extralobar sequestration, it is usually left sided, solid, and seen earlier in gestation, usually in the second trimester, has higher-amplitude echoes, and grows in proportion to the patient. 19 The detection of a systemic feeding vessel is considered diagnostic.…”

Fetal retroperitoneal pulmonary sequestration with an atypical vascular pattern

“…Sonographically, fetal abdominal PS usually presents as an echogenic, homogeneous mass, with or without cystic components, located just below the diaphragm and preferentially on the left side (Carpentieri et al, 2000;Dhingsa et al, 2003;Laje et al, 2006;McNamara and Levine, 2005). Differential diagnosis includes angioma, duplication cyst, teratoma, adrenal hematoma, renal dysplasia, pheochromocytoma, and neuroblastoma (Carpentieri et al, 2000;McNamara and Levine, 2005).…”

“…Sonographically, fetal abdominal PS usually presents as an echogenic, homogeneous mass, with or without cystic components, located just below the diaphragm and preferentially on the left side (Carpentieri et al, 2000;Dhingsa et al, 2003;Laje et al, 2006;McNamara and Levine, 2005). Differential diagnosis includes angioma, duplication cyst, teratoma, adrenal hematoma, renal dysplasia, pheochromocytoma, and neuroblastoma (Carpentieri et al, 2000;McNamara and Levine, 2005). Remarkably, the presence of an arterial vessel on color Doppler flow mapping, branching from the aorta and feeding the mass, is the most distinctive characteristic of intrathoracic PS (Corbett and Humphrey, 2004;Dhingsa et al, 2003;Sepulveda, 2009).…”