Jackson Jonathan Ian Fairburn, Au-Yong Iain T H, Higashi Yutaro, Silverman Rafael, Clarke Christopher G D
Department of Radiology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom.
Department of Oncology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom.
BJR Case Rep. 2022 Nov 1;8(6):20220102. doi: 10.1259/bjrcr.20220102.
Mucinous colorectal adenocarcinoma represents a small proportion of all colorectal cancers, characterised by mucinous tumour components. While its pattern of metastatic spread differs from that of conventional colorectal adenocarcinoma, pulmonary metastases are commonly seen in both mucinous and non-mucinous types. The assessment of pulmonary nodules in the context of malignancy is a commonly encountered problem for the radiologist given the high prevalence of benign pulmonary lesions. Low density of a pulmonary nodule on CT evaluation is one of the recognised and well-documented features of benignity that is used in the radiological assessment of such nodules. We present three cases of patients with histologically proven mucinous colorectal adenocarcinoma with evidence of pulmonary metastases. In all cases, the metastases were of low density on CT and in one case were initially suspected to represent benign hamartomatous lesions. There has been little documented about the density of mucinous pulmonary metastases on CT. We suspect the low density seen in the metastases in each case is accounted for by their high internal mucinous components. The cases presented here demonstrate the importance of recognising that mucinous colorectal metastases can be of low density and therefore mimic benign pathology. This review may help the radiologist to consider shorter interval follow-up of such lesions in the context of known mucinous neoplasms, or to investigate for an extrathoracic mucinous carcinoma in the presence of multiple low-density pulmonary nodules.
黏液性结直肠癌占所有结直肠癌的比例较小，其特征为含有黏液性肿瘤成分。虽然其转移扩散模式与传统结直肠癌不同，但黏液性和非黏液性类型中常见肺转移。鉴于良性肺病变的高发生率，在恶性肿瘤背景下评估肺结节是放射科医生常遇到的问题。CT评估时肺结节密度低是公认且有充分记录的良性特征之一，用于此类结节的放射学评估。我们报告3例经组织学证实为黏液性结直肠癌且有肺转移证据的患者。所有病例中，转移灶在CT上均为低密度，其中1例最初被怀疑为良性错构瘤性病变。关于CT上黏液性肺转移灶密度的文献报道很少。我们怀疑每个病例中转移灶低密度是因其内部黏液成分含量高所致。本文报道的病例表明，认识到黏液性结直肠癌转移灶可为低密度并因此酷似良性病变很重要。本综述可能有助于放射科医生在已知黏液性肿瘤的情况下考虑对此类病变进行更短间隔的随访，或在存在多个低密度肺结节时排查胸外黏液性癌。
