Li Xian, Yi Wei, Zeng Qingsi
Department of Radiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China.
Department of Radiotherapy, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China.
J Thorac Dis. 2018 Dec;10(12):6501-6508. doi: 10.21037/jtd.2018.11.71.
The differential diagnosis of primary pulmonary mucoepidermoid carcinoma (PMEC) and pulmonary adenoid cystic carcinoma (PACC) is difficult, because both tumors could be similar in terms of certain characteristics on CT.
The CT findings from 24 cases of PMEC and 30 cases of PACC were retrospectively analyzed. According to the position of the lesion in airway, we divided these cases into three types: central, hilar, and peripheral.
In PMEC, there were 7 cases of central type, 14 cases of hilar type, and 3 cases of peripheral type. And, 57.1% PMEC cases of the hilar type were accompanied by distal bronchial dilatation with mucoid impaction. Patchy areas of low density were observed in 79.2% cases of PMEC. The solid part of most lesions showed moderate (37.5%) or severe enhancement (45.8%). However, in PACC, there were 24 cases of central type, 3 cases of hilar type, and 3 cases of peripheral type. PACC had more cases of central type than PMEC. Moreover, longitudinal extent greater than 3 cm was observed in 62.5% PACC cases of the central type, while infiltration of the luminal perimeter more than 1/2 perimeter was observed in 95.8% PACC cases of the central type. Patchy areas of low density were observed in 26.7% cases of PMEC. In PACC cases, the solid part of 76.7% lesions showed slight enhancement. Cavities could be observed in PMEC, but not in PACC.
PMEC and PACC have different CT features in various airway locations. PMEC is usually the hilar type, accompanied by distal bronchial dilatation with mucoid impaction. However, PACC is usually the central type, with longitudinal extent greater than 3 cm and infiltration of the luminal wall more than 1/2 perimeter. Patchy areas of low density and moderate or severe enhancement are more prominent in PMEC. However, slight enhancement is more common in PACC.
原发性肺黏液表皮样癌（PMEC）和肺腺样囊性癌（PACC）的鉴别诊断较为困难，因为这两种肿瘤在CT上的某些特征可能相似。
回顾性分析24例PMEC和30例PACC的CT表现。根据病变在气道内的位置，将这些病例分为三型：中央型、肺门型和周围型。
PMEC中，中央型7例，肺门型14例，周围型3例。肺门型PMEC病例中57.1%伴有远端支气管扩张并黏液嵌塞。79.2%的PMEC病例观察到斑片状低密度区。大多数病变的实性部分表现为中度强化（37.5%）或重度强化（45.8%）。然而，PACC中，中央型24例，肺门型3例，周围型3例。PACC中央型病例比PMEC更多。此外，中央型PACC病例中62.5%观察到纵向范围大于3 cm，而中央型PACC病例中95.8%观察到管腔周长浸润超过1/2周长。26.7%的PACC病例观察到斑片状低密度区。在PACC病例中，76.7%病变的实性部分表现为轻度强化。PMEC可观察到空洞，而PACC未观察到。
PMEC和PACC在不同气道位置具有不同的CT特征。PMEC通常为肺门型，伴有远端支气管扩张并黏液嵌塞。然而，PACC通常为中央型，纵向范围大于3 cm且管壁浸润超过1/2周长。斑片状低密度区以及中度或重度强化在PMEC中更为突出。然而，轻度强化在PACC中更为常见。
