Primary Pulmonary Lymphoepithelioma-Like Carcinoma Combined with Situs Inversus Totalis

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Primary Pulmonary Lymphoepithelioma-Like Carcinoma Combined with Situs Inversus Totalis: A Comprehensive Case Analysis

Primary pulmonary lymphoepithelioma-like carcinoma (LELC) is an exceedingly rare subtype of lung cancer, categorized under “other and unclassified carcinomas” in the World Health Organization (WHO) histologic classification of lung tumors. First described in 1987, pulmonary LELC has since been closely associated with Epstein-Barr virus (EBV) infection, particularly in Asian populations, where its incidence significantly surpasses that observed in Western demographics. This case report details a unique presentation of primary pulmonary LELC in a 58-year-old non-smoking Chinese woman with coexisting situs inversus totalis (SIT), a congenital condition characterized by a complete mirror-image reversal of thoracic and abdominal organs.

Clinical Presentation and Imaging Findings

The patient presented to Zhujiang Hospital in September 2015 with a one-month history of intermittent fatigue and mild shortness of breath. Initial evaluation through chest computed tomography (CT) revealed a solitary, well-defined nodule measuring 16 mm × 14 mm adjacent to the pleura in the superior segment of the right lower lobe (Figure 1A, 1B). Notably, further imaging confirmed the presence of SIT, with thoracic and abdominal organs, including the heart, liver, and spleen, positioned in a complete mirror-image orientation (Figure 1C, 1D). No evidence of distant metastases or lymphadenopathy was observed. Additional diagnostic investigations, including head and neck magnetic resonance imaging (MRI) and emission computed tomography (ECT), ruled out metastatic disease or primary lesions in other regions (Figure 1E, 1F).

Pathological and Molecular Diagnosis

Percutaneous transthoracic needle biopsy (PTNB) of the pulmonary nodule provided definitive histopathological confirmation. Microscopic examination revealed nests of undifferentiated epithelial tumor cells with large, oval, pleomorphic nuclei surrounded by a dense stromal infiltrate of lymphocytes and plasmacytes (Figure 2A, 2B). Immunohistochemical staining demonstrated strong positivity for cytokeratin (CK), CK/H, P63, epidermal growth factor receptor (EGFR), P53, and Ki-67, while markers such as CK7, thyroid transcription factor-1 (TTF-1), synaptophysin (SYN), CD56, and anaplastic lymphoma kinase (ALK-D5F3) were negative (Figure 2C). Crucially, in situ hybridization for EBV-encoded RNA (EBER) confirmed the presence of EBV within tumor cells (Figure 2D), solidifying the diagnosis of primary pulmonary LELC.

Surgical Management and Outcomes

Given the early-stage disease (T1N0M0) and absence of metastases, the patient underwent video-assisted thoracoscopic lobectomy. The procedure was tailored to accommodate the anatomical challenges posed by SIT, including reversed vascular and bronchial structures. Postoperative recovery was uncomplicated, and the patient received no adjuvant chemotherapy or radiotherapy. Over a follow-up period exceeding two years, surveillance imaging revealed no evidence of recurrence or complications, underscoring the favorable prognosis associated with surgically resectable pulmonary LELC.

Key Clinical and Biological Insights

  1. EBV Association and Demographic Patterns
    The etiological link between EBV and pulmonary LELC is well-established, with the virus detected in nearly all reported cases. This relationship is particularly pronounced in Asian patients, who exhibit a higher incidence of pulmonary LELC compared to Western populations. The tumor’s pathogenesis is hypothesized to involve EBV-driven oncogenesis, though precise mechanisms remain under investigation.

  2. Pathological Differentiation
    Pulmonary LELC shares histological similarities with undifferentiated nasopharyngeal carcinoma (NPC), necessitating rigorous exclusion of metastatic NPC in diagnostic workflows. In this case, head and neck MRI confirmed the absence of nasopharyngeal lesions, corroborating the primary pulmonary origin.

  3. Imaging Characteristics and Differential Diagnosis
    Radiologically, pulmonary LELC often presents as a well-circumscribed nodule or mass without specific features distinguishing it from conventional bronchogenic carcinomas. However, the absence of vascular encasement or peribronchovascular spread in this case aligned with early-stage disease.

  4. SIT and Surgical Considerations
    SIT, occurring in approximately 1 in 10,000 individuals, introduces unique technical challenges during surgery due to mirrored anatomy. Preoperative planning, including detailed CT reconstruction and intraoperative vigilance, is critical to avoid procedural errors. This case highlights successful adaptation of standard surgical techniques to accommodate anatomical anomalies.

  5. Prognostic Implications
    Pulmonary LELC is associated with a more favorable prognosis compared to other non-small cell lung cancers (NSCLCs), particularly when diagnosed at an early stage. The robust lymphocytic infiltration observed histologically may reflect an enhanced anti-tumor immune response, potentially contributing to improved outcomes.

  6. Therapeutic Strategy
    Surgical resection remains the cornerstone of treatment for localized pulmonary LELC. The role of adjuvant therapy remains unclear due to the tumor’s rarity, though platinum-based regimens analogous to those used in NPC have been anecdotally employed in advanced cases.

Broader Clinical Relevance

This case represents the first documented instance of pulmonary LELC coexisting with SIT, expanding the spectrum of malignancies associated with this congenital anomaly. Previous reports have described SIT in conjunction with gastrointestinal and pancreatic tumors, but never with pulmonary LELC. The coexistence of these two rare conditions underscores the importance of meticulous diagnostic evaluation and tailored therapeutic approaches.

From a pathogenic perspective, the potential interplay between SIT and oncogenesis warrants further exploration. While no direct mechanistic link has been established, altered embryological development in SIT could theoretically influence microenvironmental factors affecting tumor initiation or progression.

Conclusion

The management of this rare dual pathology—primary pulmonary LELC and SIT—exemplifies the integration of advanced imaging, histopathological expertise, and adaptive surgical techniques. The case reinforces key clinical tenets: the prognostic significance of EBV status in pulmonary LELC, the necessity of excluding nasopharyngeal primaries, and the importance of anatomical awareness in SIT-associated surgeries. Long-term follow-up data from this patient contribute to the growing evidence supporting favorable outcomes for early-stage pulmonary LELC treated with surgical resection alone.

https://doi.org/10.1097/CM9.0000000000000039

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