Primary Small Cell Carcinoma Of The Bladder: A Case Report And Review Of The Literature

摘要

Primary small cell carcinoma of the bladder (SCCB) is a rare disease entity. Despite its aggressive course, there is not a consensus on the optimal therapy for this process. We present a case of locally advanced SCCB managed with chemoradiation and provide a review of the contemporary literature. A 90-year-old woman with gross hematuria was found to have a large, locally invasive bladder tumor on radiographic studies. SCCB was confirmed histologically from the transurethral resection specimen. The patient’s comorbidities made her unfit for radical surgery along with intolerance to chemotherapy. The patient is pursuing palliative radiation for her symptom. Introduction Small cell carcinoma (SCC) accounts for 20-30% of the diagnosis of lung cancer. This histology is not only limited to the lung; extrapulmonary sites such as gastrointestional and genital urinary tracts are usually associated with an aggressive clinical course. Primary small cell carcinoma of the bladder (SCCB) is a rare entity accounting for less than 1% of all bladder tumors [1]. Since the first published case in 1981, this disease process is only described in small series and case reports [2]. Its origin is still unknown currently; several theories such as malignant transformation of neuroendocrine cells or metaplastic transformation of other high-grade malignancies are being debated [3]. Regardless of its unproven pathogenesis, extrapulmonary SCC is associated with an aggressive course with early metastasis and high disease-specific mortality. Due to its rarity, there is not a consensus on the optimal therapy for this aggressive disease. We report a case of invasive primary SCCB being managed with non-operative therapy. Case Report A 90-year-old woman with multiple comorbidities was admitted to our hospital for congestive heart failure exacerbation and gross hematuria. The patient’s performance status was two to three. Radiographic workup with computed tomography (CT) and pelvic ultrasound showed a large tumor arising from the lateral wall of the bladder [Figure 1]. The mass appeared echogenic with increased vascularity. The largest diameter measured approximately seven cm. The tumor appeared locally invasive without any evidence of hydronephrosis, lymphadenopathy or abdominal metastasis. Cystoscopic evaluation showed a large friable tumor on the left, superior bladder wall with active bleeding. Biopsy of the tumor was performed, and the bleeding was controlled. Pathological examination of the specimen revealed: atypical cells with irregular nuclei and high nuclei to cytoplasm ratio on medical cytology [Figure 2], malignant cells with epithelial origin on immunocytology [Figure 3], and morphologically small cells with minimal cytoplasm and hyperchromatic nuclei on hematoxylin and eosin staining [Figure 4]. The morphology and immunophenotype of the specimen are consistent with small cell carcinoma. A complete metastatic workup was performed: CT of the brain and chest were negative for additional disease. Due to her comorbidities and performance status, the patient was not an optimal candidate for radical cystectomy with pelvic exenteration. The patient was started on an abbreviated chemotherapy regiment consisted of oral etoposide at 50 mg once a day. After one week of therapy, etoposide was stopped due to a significant decrease of white blood cell count. Patient is alive with persistent gross hematuria, four months after diagnosis. We are pursing palliation for her symptomatic disease.