Pulmonary spindle cell carcinoma with unusual morphology: A rare case report and review of the literature

Abstract

Rationale: Pulmonary spindle cell carcinoma (PSCC) is a highly malignant carcinoma that often exhibits the histopathological characteristic of cell pleomorphism.

Patient concerns: Here, we report a PSCC case in a 59-year-old woman with multiple metastases. The pathological manifestation of this case did not show high-grade pleomorphism or atypia, and was easily mimicked by other borderline or low-grade malignant tumors such as an inflammatory myofibroblastic tumor (IMT).

Diagnoses: Based on the results of immunohistochemistry and fluorescence in situ hybridization after the operation, IMT was ruled out, and PSCC was confirmed.

Interventions: Resection of the right middle lobe and dissection of the lymph nodes were performed. The patient was given 2 cycles of chemotherapy with cisplatin and 1 cycle of radiotherapy after the operation.

Outcomes: Metastatic lesions in the left kidney, the right lung, the first thoracic vertebrae, the retroperitoneal lymph nodes, and the mediastinal lymph nodes were identified by positron emission tomography/computed tomography 4 months after the operation, and the patient died 2 months later.

Lessons: PSCC is a highly malignant carcinoma, but it rarely shows a low-grade malignant histological morphology. So, efforts should be focused on differentiating it from other borderline or low malignant tumors (such as IMT) to avoid misdiagnosis.

Figure 1

Computed tomography (CT) scan and enhanced CT findings. There is no shadow on the bronchus of the middle right lung. (A) A circular 4.8 × 4.0 cm low-density shadow in the lung field is visible (arrows), with a density similar to a liquid with indistinguishable borders. (B) Enhanced CT enhances the borders but not the center, thus forming a central low-density area.

Figure 2

Histopathological findings. (A) The tumor tissue borders were clear. (B) The tumor cells are completely composed of spindle cells arranged in bundles and swirls. No obvious cell pleomorphism is observed. (C) Mitosis is obvious in some regions. (D) Coagulation necrosis is observed in some regions.

Figure 3

Immunohistochemical staining. (A) CK (pan) showed tumor cells were positive. (B) CK7 showed positive in tumor cells. (C) TTF-1 was expressed in only type II alveolar epithelial cells, but tumors cells were negative. (D) Vimentin showed positive tumor cells. (E) CD34 showing vascular positive and tumor cells (−). (F) β-Catenin showed as cytoplasm positive in tumor cells, but were negative in tumor cells nuclei. (G) ALK showed tumor cells were negative. (H) Ki-67 showed a high tumor proliferative index (about 70%+). ALK = anaplastic lymphoma kinase, TTF-1 = thyroid transcription factor-1.

Figure 4

Positron emission tomography (PET)/computed tomography (CT) findings. (A) PET/CT (bottom) showing an area of abnormally increased radiopharmaceutical uptake in the liver (indicated by the coordinate line). The maximum SUV was 17.0. No obvious abnormality is visible in the corresponding CT (top). (B) CT showing right pulmonary nodules. FDG uptake is increased and the maximum SUV was 3.6. (C) Increased circular FDG uptake in the left kidney. The maximum SUV was 11.4. (D) Increased uptake in the first thoracic vertebrae. The maximum SUV was 7.8. (E) PET/CT showing increased nodular FDG uptake in the left renal anterior region. The maximum SUV was 13.5. (F) PET/CT showing increased FDG uptake in the mediastinum. The maximum SUV was 9.2. FDG = fluorodeoxyglucose, SUV = standardized uptake value.