Syndrome of inappropriate antidiuretic hormone secretion in a patient with cryptococcal meningoencephalitis: a hidden mediastinal small cell carcinoma

Cryptococcus neoformans infection in malignancy

Cryptococcosis is an opportunistic invasive fungal infection that is well described and easily recognised when it occurs as meningitis in HIV-infected persons. Malignancy and its treatment may also confer a higher risk of infection with Cryptococcus neoformans, but this association has not been as well described. A case of cryptococcosis in a cancer patient is presented, and all cases of coincident C. neoformans infection and malignancy in adults published in the literature in English between 1970 and 2014 are reviewed. Data from these cases were aggregated in order to describe the demographics, type of malignancy, site of infection, clinical manifestations, treatment and outcomes of cryptococcosis in patients with cancer. Haematologic malignancies accounted for 82% of cases, with lymphomas over-represented compared to US population data (66% vs. 53% respectively). Cryptococcosis was reported rarely in patients with solid tumours. Haematologic malignancy patients were more likely to have central nervous system (P < 0.001) or disseminated disease (P < 0.001), receive Amphotericin B as part of initial therapy (P = 0.023), and had higher reported mortality rates than those with solid tumours (P = 0.222). Providers should have heightened awareness of the possibility of cryptococcosis in patients with haematologic malignancy presenting with infection.

Mediastinal small cell carcinoma: a unique clinical entity?

PURPOSE

Mediastinal small cell carcinoma (MSCC) is a rare tumor with limited published literature. In view of diagnostic confusion pertaining to this tumor, we investigated its origin, clinical features, management and survival.

METHODS

Clinical data of MSCC patients were retrospectively reviewed. Eligible patients showed pathologically proven small cell carcinoma (SCC) with the primary lesions confined to the mediastinum. Survival information was collected through follow-up studies.

RESULTS

Among 25 MSCC patients identified, 22 were classified to have limited disease (LD), while 3 were with extensive disease (ED). The 5 patients (20%) underwent surgery and 20 patients (80%) underwent non-surgical treatment. The 4 patients with LD MSCC received chemotherapy alone, while 13 of them received chemoradiotherapy. Overall median survival time (MST) of all patients was 22 months, and the 1-, 3- and 5-year overall survival rates were 67.4, 16.8, and 8.4%, respectively. The MST of LD and ED patients separately was 23 and 8 months, respectively, with significant difference (P = 0.005). But, the MST of patients who received surgical and non-surgical treatment was 25 and 21 months, respectively, with no significant difference (P = 0.757). The MST of LD patients receiving chemotherapy and chemoradiotherapy was 12 and 29 months, respectively, but somehow did not show significant difference (P = 0.482).

CONCLUSIONS

Our data suggested that MSCC may be a separate clinical entity like extrapulmonary small cell carcinomas (EPSCCs). Despite, multimodal treatment is currently the main treatment option, but for patients with LD MSCC, chemoradiotherapy is recommended to be preferred treatment modality.

Primary small cell carcinoma of the mediastinum: a case report with immunohistochemical and molecular genetic analyses of KIT and PDGFRA genes

The author reports herein an extremely rare case of primary small cell carcinoma of the mediastinum with an emphasis on KIT and PDGFRA genes. A 66-year-old man was found to have a mediastinal tumor on a routine chest X-ray examination, and was admitted to our hospital. Imaging modalities revealed a 5 x 4 cm tumor in the middle mediastinum near the bronchial carina. No other tumors were detected in the body including the lungs. Video-assisted thoracoscopy confirmed the mediastinal tumor, and a large incisional biopsy was performed. The tumor was histologically small cell carcinoma. An immunohistochemical study revealed positive reactions for cytokeratins (AE1/3, polyclonal), synaptophysin, neuron-specific enolase, CD56, KIT, and PDGFRA, and negative reactions for chromogranin, CEA, CD45, CD20, and CD3. Ki-67 labeling showed a value of 80%. A molecular genetic analysis using PCR-direct sequencing identified no mutations of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) genes. The patient received radiation and chemotherapy, and the tumor was fully resolved. The patient has remained free of recurrence for 6 years after the first presentation. The present case is the first reported case of primary small cell carcinoma of the mediastinum with an examination of KIT and PDGFRA expressions and KIT and PDFGRA gene mutations.