MATERIALS AND METHODS: Imaging studies of 22 patients 12 men, mean age 60 years with histopathologically confirmed diagnosis, evaluated in the authors's institution during the last five years were retrospectively reviewed by two radiologists, with findings being consensually described focusing on changes observed at computed tomography.
Only one typical carcinoid presented the characteristic appearance of central endobronchial nodule with distal pulmonary atelectasis, while the others were pulmonary nodules or masses. The atypical carcinoids corresponded to peripheral heterogeneous masses.
One out of the three LCNCs was a peripheral homogeneous mass, while the others were ill-defined and heterogeneous. The 11 SCLCs corresponded to central, infiltrating and heterogeneous masses with secondary pleuropulmonary changes.
Keywords: Computed tomography; Lung neoplasms; Neuroendocrine tumors. Primary neuroendocrine tumors of the lung NTLs originate either from Kulchitzky cells, neuroepithelial bodies or from pluripotent stem cells which are present in the bronchial mucosa, with similar pathological features, and being capable of producing and secreting peptide hormones and neuroamines 2.
Since the early 's, because of its clinical and histological characteristics, SCLC is neuroendocrine cancer type as a neuroendocrine neoplasia of the lung.
In the present study, the authors describe the main imaging findings in a series of histopathologically confirmed cases of NTL, with emphasis on computed tomography CT findings. Also, the authors make a brief description of the main clinical data, including information on the evolution of the cases, correlating them with radiological and anatomopathological data.
Only histopathologically confirmed cases of primary neuroendocrine tumors of the lung were included in the present study. A total of 22 patients 12 men, mean age of 60 years, ranging from 32 to 78 years were studied.
Considering the retrospective nature of the study, with exams that are part of the clinical routine in the assessment of such patients, it exempted a term of free and informed consent in addition to the one obtained previously to the performance of the exams.
Clinical data was obtained after review of the patients' records and imaging studies retrieved from the electronic file system of the authors' institution. Images were reviewed by two radiologists, and the findings were described in consensus.
The lesions were evaluated with respect to morphological characteristics, location, dimensions, presence of calcifications, associated changes in the pulmonary parenchyma, lymph node enlargement and presence of distant metastases.
All the imaging studies stored in the electronic file system were reviewed, including plain radiographs and magnetic resonance imaging MRI studies, but the reviewers have particularly focused on the description of CT findings, which is currently the most accurate radiological method and most commonly utilized in the evaluation of lung tumors.
In spite of not neuroendocrine cancer type related to the main objective of the present study, the post-treatment follow-up exams, whenever available, were also reviewed for correlation of imaging findings with the clinical progression according to the type of neoplasia identified at the anatomopathological study.
The description of symptoms was varied, including dyspnea, chronic coughing, chest pain and "repeated pneumonias". Along the medical records neuroendocrine cancer type process, data confirming the presence of paraneoplastic syndrome due to ectopic production of hormones were not found for any of the does hpv virus cause herpes. As regards histological type, the lesions of the 22 patients included: five typical carcinoid lesions, three atypical carcinoid lesions, three LCNCs and 11 SCLCs Table 1.
Plain radiography could identify the atelectasis in the upper right lobe. At Neuroendocrine cancer type, the ovoid endobronchial nodule was identified in neuroendocrine cancer type origin of the right upper lobe bronchus. The other cases of typical carcinoid lesion presented as lung nodules or masses, either centrally or peripherally located, with smooth or lobulated margins, homogeneous soft tissue density, and dimensions ranging from 2.
No patient presented lymph node enlargement or metastatic lesions at the initial presentation of the disease. Distal, secondary changes were described in all cases, mainly represented by areas of inflammatory consolidation or atelectasis. All five patients were submitted to surgical resection either segmentectomy or lobectomy and only one patient presented recurrence of the disease in the clinical follow-up, with mediastinal lymph node enlargement identified six years after diagnosis Figure 3.
One patient with a typical carcinoid neuroendocrine cancer type also underwent MRI, which demonstrated the presence of a well defined nodule in neuroendocrine cancer type left lower lobe with intermediate signal intensity on T1-weighted and hyperintense signal on T2-weighed sequences, also with restriction in diffusion weighted imaging and prominent contrast-enhancement more noticeable in delayed phases and with homogeneous appearance Figure 2.
The three cases of atypical carcinoid tumors were identified both at plain radiography and CT, described as peripheral lung masses with lobulated or irregular contours, with heterogeneous density and contrast-enhancement, dimensions ranging between 3. One lesion presented nodular calcifications identified at plain radiography, but best characterized at CT. One patient already presented lymph nodes enlargement and lesions compatible with metastases bone and liver at the initial assessment and evolved to death.
Another patient presented suspicious metastic liver lesions at neuroendocrine cancer type moment of the diagnosis, progressing with enlargement of the lesions progressive disease and at the time of the present study such patient was undergoing systemic therapy.
In one patient neuroendocrine cancer type lesion was resected and no recurrence has been cancer de san cu metastaze cerebrale at most-recent follow-up.
Of the three LCNC patients, one presented a peripheral well-defined mass with homogeneous density, while the other two patients presented heterogeneous, peripheral, ill-defined masses with irregular contours in association with important pleuropulmonary changes Figure 5. The lesions dimensions ranged from 4.
The two patients presenting with heterogeneous lesions already presented lymph nodes enlargement and distant metastatic lesions at their initial assessment, and underwent non-surgical therapy, but evolved with progressive disease at follow-up and, later, death.
The other patient presented progressive, metastatic disease and currently is still undergoing local and systemic treatment and has not been submitted to surgical resection of the lung lesion.
All of the 11 cases of SCLC presented as lesions of similar radiological appearance, characterized as central masses associated with coalescent lymph node enlargement with infiltrating and heterogeneous aspect, invading vascular structures as well as the adjacent tracheobronchial tree Figure 6. Other associated thoracic changes were described in all cases, such as secondary lung lesions, pneumonia, atelectasis, pleural effusion and pleural thickening.
At plain radiography, the characterization of the masses was in general more difficult, particularly in the presence of lung atelectasis and large pleural effusion. In general, the lesions that could be measured were larger than 5. Calcifications were not identified in any lesion. In the present study, the authors retrospectively reviewed imaging findings in patients with histopathologically confirmed NTL diagnosed in their institution, with emphasis on CT findings.
The authors describe five cases of typical carcinoid tumors and three cases of atypical carcinoid tumors. Atypical carcinoid tumors are assciated with smoking, most commonly affecting male patients and at older ages 59 years, on averagewhile typical carcinoid tumors lack established association with smoking, affecting younger patients of both genders. Typical carcinoid tumors represent the most common lung neoplasia in the childhood and most frequently are diagnosed at less advanced clinical stages, hpv wart biopsy with metastases and progressing with longer survival as compared neuroendocrine cancer type atypical carcinoid tumors 8.
In the present study, the authors found only one case of central endobronchial nodule characteristic of typical carcinoid tumor, but atypical carcinoid tumors were found as larger and more heterogeneous peripheral masses, more frequently with metastases at diagnosis or follow-up, likewise described in neuroendocrine cancer type literature.
Among the typical carcinoid tumors, only one presented late recurrence of the disease, in the form of mediastinal lymph node enlargement identified at CT follow-up, years after the primary lesion resection.
According to the medical literature, imaging findings of both typical and atypical carcinoid tumors are similarly described, neuroendocrine cancer type mainly found as well-defined nodules or masses, sometimes lobulated, and when elongated, with the longer axis parallel to the bronchi.
Carcinoid tumors tend to be well vascularized, with prominent contrast enhancement, which also aids in neuroendocrine cancer type differentiation between lesions and the commonly associated distal secondary changes pneumonia, atectasis and bronchi with mucoid impaction 9.
Despite their similar characteristics, one describes that the presence of a central, well-defined nodule causing narrowing, deformity or obstruction of a bronchus, especially if containing calcifications, is suggestive of a typical carcinoid tumor. On the neuroendocrine cancer type hand, atypical carcinoid tumors tend to be larger, more peripheral distal to the segmental bronchus and more heterogeneous, besides presenting a higher incidence of metastatic lesions at the diagnostic imaging In the present study, the authors described three cases of LCNC, all of them presenting as peripheral heterogeneous masses associated with metatastic disease, and none of the lesions with calcifications.
LCNC was the fourth and last tumor subtype to be recognized as a neuroendocrine tumor of the lung, with characteristics that make it different from the typical and atypical carcinoid tumors as well as from the SCLC 3.
It is predominantly found in men 2. Pleural thickening or effusion are also commonly described Interestingly, in the present review, one patient was a year-old woman. In hpv mode de transmission present study, the authors described 11 cases of patients with SCLC. Lesions were similar to those described as most characteristic in the medical literature, with no isolated findings of nodule or peripheral mass.
The literature reports that, at the moment of diagnosis, the patient usually presents advanced disease with neuroendocrine cancer type, mainly to bones, liver, adrenal glands or brain Findings of atectasis, other lung lesions and pleural effusion are common.
In the present study, lesions with calcifications were not found. More rarely, SCLC presents as a peripheral lung lesion without lymph node enlargement, and in such cases it may be confused with other types of bronchogenic carcinomas and with the other NTLs 1, Probably, the present study's sample of SCLC was underestimated, considering its prevalence and the characteristic of specialized reference hospital of the authors' institution.
Archive of Clinical Cases
The authors believe that such limitation of the present study was related to the fact that only cases with histopathological and immunohistochemical confirmation and radiological exams performed in their own institution were included. In this series of cases, only one patient with lung neoplasia underwent MRI, with a typical carcinoid lesion presenting as a lung nodule. The role of MRI in the evaluation of lung neoplasms is increasing, particularly in the staging of lesions and in the clinical follow-up of the treatment.
However, little has been reported in the literature 15 about MRI in the evaluation of NTL, and its role, particularly regarding diagnostic accuracy in the different histological types of Neuroendocrine cancer type, still requires further investigation.
Bronchogenic carcinoma: radiologic pathologic correlation. Distinctive clinical and therapeutic aspects of the syndrome associated with bronchial carcinoid tumors.