Immune-Mediated Diseases and Immunodeficiencies Associated with Thymic Epithelial Neoplasms

Pure white cell aplasia before and after thymectomy in the rare conundrum of thymoma: A case report and review of the literature

RATIONALE

Pure white cell aplasia (PWCA) is a rare paraneoplastic syndrome that occurs in patients with thymomas. Currently, the pathogenesis and treatment of this disease remain in the exploratory stage.

PATIENT CONCERNS

We report a 68-year-old woman with thymoma experienced PWCA involvement as her first presentation. The patient had high fever and agranulocytosis at the onset of the disease. The white blood cell count in the complete blood count was 1.9 × 109/L with a neutrophil of 0.1 × 109/L. The bone marrow aspirates showed decreased granulocyte proliferation. Computed tomography showed a large mass in the anterior mediastinum.

DIAGNOSES

The final diagnosis of our patient was PWCA and thymoma.

INTERVENTIONS

She underwent a thymectomy and cyclosporine A administration during first remission.

OUTCOMES

Long-term remission was achieved following the readministration of cyclosporine A after the disease recurrence.

LESSONS

PWCA or agranulocytosis with thymoma has been confirmed to be an extremely rare disease. Thymomas with PWCA correlate with autoimmunity. From this case study and the literature review, we concluded that the pathogenesis of thymomas in PWCA is mainly related to the activation of autoreactive T cells. Thymectomy and the immunosuppressive drug, cyclosporine A, were chosen for treatment. The patient's granulocyte levels were unable to recover after surgery because of the inability to promptly clear activated T cells. After surgery, cyclosporine A continued to take for a long time. Thymectomy combined with prolonged cyclosporine A administration may be an effective method for treating this rare disease.

Insulinoma-associated-1 (INSM1) expression in thymic squamous cell carcinoma

Thymic squamous cell carcinoma (TSC) presents distinct immunohistochemical features with its expression of CD5 and CD117, both of which are rarely expressed in squamous cell carcinoma in other organs. We found insulinoma-associated-1 (INSM1) expression in some TSCs; thus, a series of thymic tumors were examined retrospectively. Using surgically resected thymic tumors (TSC, n = 35; thymic atypical carcinoid [TAC], n = 4; and thymoma, n = 112) and non-neoplastic thymic tissue (n = 26), we evaluated immunohistochemically the expressions of INSM1, ASCL1, SOX2, NE markers (synaptophysin, chromogranin A, and CD56), and conventional TSC markers (CD5 and CD117). INSM1 was expressed in 22 TSCs (63%), whereas the positive frequencies of synaptophysin, chromogranin A, and CD56 were limited to 13, 10, and 1 cases, respectively. The discordance was highly contrasted with concordantly positive TACs. INSM1 and NE makers were rarely expressed in thymomas. INSM1 expression in TSCs was also associated with CD5 expression, which was significantly less frequent in INSM1-negative TSCs. INSM1, ASCL1, and SOX2 expressions were correlated with one another, but none of the single transcription factors or their combinations is associated with NE expression. The non-neoplastic medullary thymic epithelium was dispersedly positive for INSM1, particularly around Hassall's corpuscles. Despite positive INSM1, a significant decrease in the frequency of NE maker expression may present as a diagnostic pitfall in TSCs. Furthermore, the discordance, which was inherent in the non-neoplastic thymic epithelium, might be a characteristic feature in TSCs.

Clinical manifestations and long-term prognosis of Good syndrome: Results from a single-center cohort study from China

OBJECTIVE

To describe clinical features and long-term prognosis in patients with Good syndrome (GS).

METHODS

We retrospectively reviewed medical records of GS patients at Peking Union Medical College Hospital from January 2001 to May 2019. Data regarding clinical manifestations and treatments were collected. Patients were routinely followed-up via clinical and telephone interviews, and survival analysis was performed with Kaplan-Meier analysis.

RESULTS

Twenty-four patients were identified, including eight males and 16 females, with a median age at diagnosis of 58 years (interquartile range [IQR], 52-62 years). Twelve patients (50%) had autoimmune manifestations. Multi-organ involvements included musculoskeletal (37.5%), respiratory (33.3%), gastrointestinal (29.2%), hematologic (29.2%) systems, et.al. Infections were detected in 23 (95.8%) patients, mostly located in lung (69.6%), blood (26.1%), and gastrointestinal tract (21.7%). Thymectomy was performed in 23 patients, with the most common histology of type AB (10, 47.6%). Twenty-one patients were consecutively followed-up with a median follow-up of 84 (IQR, 48-116) months and 11 (52.4%) died, mainly due to infection (8/11, 72.7%). The 5- and 10-year survival rates were 90% (95% confidence interval [CI], 77.8-100%) and 38.5% (95% CI, 19.6-75.5%), respectively.

CONCLUSION

GS patients tended to present with various infections and autoimmune manifestations. The 10-year survival rate from the Chinese population was poor, mainly due to infections.

Perioperative risk factors for occurrence of myasthenia gravis after thymectomy in patients with thymoma

OBJECTIVES

The goal of this study was to identify the relationship between clinical characteristics and the occurrence of postoperative myasthenia gravis (PMG) in patients with thymomas and to further identify the relationship between PMG and prognosis.

METHODS

Thymoma patients who had surgery at the First Affiliated Hospital of Sun Yat-sen University between July 2004 and July 2016 were reviewed and those who had no previous symptoms of myasthenia gravis were selected for further investigation. In total, 229 patients were included in the study; their clinical characteristics were gathered and analysed.

RESULTS

Among the 229 patients, 19 (8.3%) had PMG. The time between the operation and the onset of myasthenia gravis was 134 days on average (range 2-730 days). Patients experiencing PMG showed a lower rate of complete thymoma resection (73.7% vs 91.4%; P = 0.014) and total thymectomy (63.2% vs 82.9%; P = 0.035) compared with those who did not. Univariable and multivariable logistic regression revealed that thymomectomy [odds ratio (OR) 2.81, 95% confidence interval (CI) 1.02-7.77; P = 0.047] and incomplete tumour resection (OR 3.79, 95% CI 1.20-11.98; P = 0.023) were associated with the occurrence of PMG. Multivariable Cox regression showed that the PMG was not related to overall survival (P = 0.087).

CONCLUSIONS

This study revealed that incomplete tumour resection and thymomectomy were independent risk factors for PMG in thymoma patients with no previous history of myasthenia gravis.

A Rare Complication of Thymoma: Pure White Cell Aplasia in Good's Syndrome

Pure white cell aplasia (PWCA) is a rare manifestation of thymoma. It is characterized by agranulocytosis with absent myeloid precursors in the bone marrow and normal hematopoiesis for other cell lines. Here we describe a 65-year-old female patient who presented with three days of fever and night sweat. Chest CT revealed an anterior mediastinal mass. A biopsy of the mass confirmed a diagnosis of thymoma mixed type A and B2. The patient developed a severe neutropenia, and her bone marrow revealed significantly decreased neutrophil-lineage cells, rare to absent B cells, and defective T cells, consistent with PWCA. Following thymectomy, a complete resolution of PWCA was achieved via multimodality therapy of intravenous immunoglobulins, granulocyte colony-stimulating factor, and immunosuppressant. This report highlights the care complexity regarding treatment choices and decision to perform thymectomy in patients presenting with PWCA.

An updated review on phenocopies of primary immunodeficiency diseases

Primary immunodeficiency diseases (PIDs) refer to a heterogenous group of disorders characterized clinically by increased susceptibility to infections, autoimmunity and increased risk of malignancies.

These group of disorders present with clinical manifestations similar to PIDs with known genetic defects but have either no genetic defect or have a somatic mutation and thus have been labelled as “Phenocopies of PIDs”. These diseases have been further subdivided into those associated with somatic mutations and those associated with presence of auto-antibodies against various cytokines.

In this review, we provide an update on clinical manifestations, diagnosis and management of these diseases.

Acquired immunodeficiency associated with thymoma: a case report

Background

Acquired immunodeficiency associated with thymoma is a rare disorder. Here we reported a case of acquired immunodeficiency with thymoma, with an unusual pattern of low CD4⁺ count with normal gammaglobulin levels.

Case presentation

A 70-year-old man presented to the emergency room of our hospital with a high-grade fever, headache, and nausea. He had a five-year history of unresectable thymoma treatment, including several cytotoxic regimens. He had received thoracic palliative radiotherapy 2 months prior to the emergent visit. During the previous month, he had experienced multiple febrile episodes, dry cough, fatigue, weight loss, and watery diarrhea. Upon admission, he had a high-grade fever, nausea, and immobility. Physical examination revealed indistinct consciousness, neck stiffness, and oropharyngeal candidiasis. Both cerebrospinal fluid and blood cultures yielded multiple short chains of Gram-positive rods later identified as Listeria monocytogenes, so he was diagnosed with Listeria meningitis. Intravenous administration of antibiotics was initiated, and the patient fully recovered and was discharged. Additional examination found normal immunoglobulin levels. Peripheral-blood cell counts revealed low CD4⁺ cell count (108 CD4⁺ cells/μl). His CD4⁺ cell count remained low after discharge.

Conclusions

Our findings suggest that physicians need to be aware of severe infections due to immunodeficiency with thymoma.

Emerging clinical phenotypes associated with anti-cytokine autoantibodies

Anti-cytokine autoantibodies (AAbs) are frequent and involve a very large panel of cytokines both in healthy subjects and in patients with various pathological conditions. In healthy individuals, anti-cytokine AAbs are described as a part of the natural AAb repertoire and are thought to contribute to the fine regulation of cytokine homeostasis. In some patients, neutralizing AAbs targeting cytokines required for the immune protection against specific microbes may induce acquired immunodeficiency leading to very specific infectious phenotypes. For instance, anti-IFNγ AAbs may induce disseminated non-tuberculous mycobacterial infections; anti-IL-17 AAbs are associated with the development of chronic mucosal candidiasis, and anti-IL-6 AAbs with severe staphylococcal or streptococcal infections. In patients with autoimmune diseases, AAbs directed against pathogenic cytokines are able to influence the course of the diseases. In lupus patients, neutralizing anti-IFNα and anti-TNFα AAbs are associated with a decreased bioactivity of the corresponding cytokine and a lower disease severity. Similarly, anti-IL-1α AAbs are associated with nondestructive forms of chronic polyarthritis. More surprisingly, neutralizing anti-BAFF AAbs are observed in the serum of lupus patients with elevated IFNα signature and higher disease activity. In this review, we summarize the current literature describing the different phenotypes and the main mechanisms associated with the occurrence of anti-cytokine AAbs.