Primary signet-ring cell carcinoma of the lung: A report of seven cases

A prognostic framework for predicting lung signet ring cell carcinoma via a machine learning based cox proportional hazard model

PURPOSE

Signet ring cell carcinoma (SRCC) is a rare type of lung cancer. The conventional survival nomogram used to predict lung cancer performs poorly for SRCC. Therefore, a novel nomogram specifically for studying SRCC is highly required.

METHODS

Baseline characteristics of lung signet ring cell carcinoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression and random forest analysis were performed on the training group data, respectively. Subsequently, we compared results from these two types of analyses. A nomogram model was developed to predict 1-year, 3-year, and 5-year overall survival (OS) for patients, and receiver operating characteristic (ROC) curves and calibration curves were used to assess the prediction accuracy. Decision curve analysis (DCA) was used to assess the clinical applicability of the proposed model. For treatment modalities, Kaplan-Meier curves were adopted to analyze condition-specific effects.

RESULTS

We obtained 731 patients diagnosed with lung signet ring cell carcinoma (LSRCC) in the SEER database and randomized the patients into a training group (551) and a validation group (220) with a ratio of 7:3. Eight factors including age, primary site, T, N, and M.Stage, surgery, chemotherapy, and radiation were included in the nomogram analysis. Results suggested that treatment methods (like surgery, chemotherapy, and radiation) and T-Stage factors had significant prognostic effects. The results of ROC curves, calibration curves, and DCA in the training and validation groups demonstrated that the nomogram we constructed could precisely predict survival and prognosis in LSRCC patients. Through deep verification, we found the constructed model had a high C-index, indicating that the model had a strong predictive power. Further, we found that all surgical interventions had good effects on OS and cancer-specific survival (CSS). The survival curves showed a relatively favorable prognosis for T0 patients overall, regardless of the treatment modality.

CONCLUSIONS

Our nomogram is demonstrated to be clinically beneficial for the prognosis of LSRCC patients. The surgical intervention was successful regardless of the tumor stage, and the Cox proportional hazard (CPH) model had better performance than the machine learning model in terms of effectiveness.

A case report of anterior mediastinal signet ring cell carcinoma

RATIONALE

Anterior mediastinal signet ring cell carcinoma (SRCC) is a rare tumor that has only been reported in two cases of thymic cancer. Positive immunohistochemistry (IHC) staining for caudal-type homeobox (CDX) 2, cytokeratin (CK) 20 and special AT-rich binding protein (SATB) 2 usually indicate gastrointestinal tumors but begin to appear in thymic cancers with enteric differentiation. Here, we describe a case of the anterior mediastinal SRCC with enteric differentiation who was correctly treated with surgery and chemo-radiation and was alive after four months.

PATIENT CONCERNS

A 48-year-old female presented without chest and lung symptoms had an anterior mediastinal mass during a routine physical examination. Laboratory examinations showed an elevated level of serum carbohydrate antigen (CA)-125 at 73.63 U/mL. Chest computed tomography (CT) showed an irregular soft tissue density shadow with heterogeneous enhancement in the anterior mediastinum. The tumor had invaded the pericardium, the left septal nerve and the innominate and was completely removed after anterior mediastinal surgery. Postoperative pathological examinations revealed signet ring cell features and positive staining for CDX2, CK20, SATB2 and Ki-67 (Li: 70%). The samples were negative for cluster of differentiation (CD)-5, CK7, thyroid transcription factor (TTF) 1, NapsinA, CerbB-2, P53 and PD-L1 by IHC examinations. The suspected diagnosis was an anterior mediastinal SRCC that had originated in the digestive system.

DIAGNOSIS

The patient was diagnosed with anterior mediastinal SRCC.

INTERVENTIONS

The patient was treated with surgery and combined chemo-radiotherapy.

OUTCOMES

The patient had no recurrence or metastasis after five months.

LESSONS

We describe a rare case of the anterior mediastinal SRCC of unknown origin. Our case, for the first time shows that surgery combined with chemo-radiotherapy is an effective treatment regimen for anterior mediastinal SRCC.

A case report of primary signet ring cell carcinoma of the lung: imaging study and literature review

Signet ring cell carcinoma (SRCC) is a subtype of adenocarcinoma with characteristics of strong invasion and a poor prognosis. While it can occur in various organs, including the stomach, colon, esophagus, bladder, prostate, pancreas, and breast, primary lung SRCC is rare, and most SRCC found there are from gastrointestinal metastasis. Reports on primary lung SRCC are few and the aim of this study is to describe the imaging, histopathological, and immunohistochemical characteristics of a case of primary lung SRCC in our hospital. A 68-year-old female with no smoking history was admitted with recurrent cough, chest pain, and dyspnea of 2 months duration. Computed tomographic (CT) chest showed multiple solids nodules of different sizes and mass in the left upper lobe, lower lobe, and subpleural region. Multiple enlarged lymph nodes were seen in the mediastinum and left hilum. The aim of this paper is to improve the understanding of this tumor. A literature review identified 15 cases of primary lung SRCC with available CT imaging. Except for two patients with multiple ground glass nodules and multiple small nodules, the rest were solid, and ranged in size from 1.0 to 8 cm. Only one patient had a cavity in the solid lesion. Immunohistochemical stains for thyroid transcription factor-1 (TTF-1) (13/13) and CK7 (12/12) showed positive reaction in all cases evaluated, and napsin A (3/4) were also positive, while all cases including CK20 (12/12) and CDX2 (6/6) were negative.

Primary signet-ring cell carcinoma of the lung in an HIV-positive patient

Primary lung signet-ring cell carcinomas are a rare entity and only a few cases of pure signet-ring cell carcinomas of the lung are reported in the English literature. They usually have an aggressive behavior and a poor prognosis because in most cases they are identified at an advanced stage. We present a unique case of primary signet-ring cell carcinoma of the lung because the patient was HIV positive, a heavy smoker, and also the tumor, discovered incidentally during chest x-ray, was a pure type of signet-ring cell carcinoma. Surgical therapy associated with chemoradiotherapy represents the gold standard in the care of these patients.