In this case, we present a 74 year old African American female with primary pleomorphic rhabdomyosarcoma of lung. This case is being reported because of the extreme rarity of primary pulmonary pleomophic rhabdomyosarcoma, particularly after 70 years of age.
The patient was a 74 year old female who presented to the Emergency Department with 3 weeks of progressive dyspnea on exertion, cough productive of blood tinged sputum, nausea and loss of appetite with a 20 pound weight loss, and fatigue. She has a 60 pack year smoking history and quit smoking 4 years ago. Her vital signs included an oral temperature of 97.9F, a blood pressure of 168/83 mm Hg, a heart rate of 110 beats per minute, and a respiratory rate of 18 breaths per minute. Her oxygen saturation was 98% while breathing oxygen at a flow rate of 2L/minute by nasal cannula. Physical examination revealed diminished breath sounds in the left lung field but was otherwise unremarkable. Chest X-ray demonstrated a pleural-based left lung mass and mediastenal widening and pleural effusion. CT scan of chest revealed a large soft tissue mass in the mediastinum and hilum as well as multiple subcentimeter nodules in the left upper lobe. Fiberoptic bronchoscopy revealed extrinsic compression of the left main stem bronchus by the mass. Transbronchial biopsies of the mass were obtained and the pleural effusion was sampled by thoracentesis. Biopsy and effusion results demonstrated large atypical cells with nuclear positivity for myf-4 (myogenin) and desmin, a pattern consistent with pleomorphic rhabdomyosarcoma. Stains for TTF-1, WT-1, CD-20, CD-30, LCA, EMA and AE1/AE3 were negative. Cancer was staged as Stage111b, after ruling out metastasis.Surgical treatment was avoided because of her poor medical status. The patient was treated with chemo-radiation. Unfortunately patient didn’t do well with treatment and expired after receiving two cycles of Chemotherapy.
Rhabdomyosarcoma (RMSC) is a rare malignant tumor of rhabdomyoblastic origin. Histologically, it may take three forms: embryonal, alveolar, and pleomorphic. The embryonal variety is most frequently encountered (75% of all RMSC) and is typically seen in those younger than 15 years of age, The alveolar type is the second most common (20% of all RMSC) and the pleomorphic RMSC is exceedingly rare. Males are affected more than females and it is rare to diagnose this disease after the age of 70. All RMSC are highly malignant tumors. The cells closely resemble those found in small cell carcinoma of the lung and can be mistaken easily. Differentiation can be made using myogenin stains which are positive in RMSC. Surgery is the best treatment but chemo-radiotherapy is an option for nonsurgical candidates.
Primary pleomorphic rhabdomyosarcoma is a rare malignancy of the lung and is extremely rare after the age of 70. It can appear histologically similar to small cell carcinoma of the lung but can be differentiated using myogenin stains. The appropriate diagnosis of PRMS is significant as it is a high-grade sarcoma, with an aggressive clinical course and grave prognosis.
Sudheer Nambiar, No Financial Disclosure Information; No Product/Research Disclosure Information