Pulmonary sarcomatoid carcinoma presenting as a necrotizing cavitary lung lesion: diagnostic dilemma

Pulmonary sarcomatoid carcinoma (PSC) is a rare histological subtype that has an aggressive course with average survival of 11-13 months.¹ In clinical practice, the possible presentations of this rare cancer are not widely known, resulting in a misdiagnosis. That is what happened with our patient, who presented with necrotizing cavitary lung lesion and soft tissue necrotizing lymphadenitis. The clinical picture was reminiscent of tuberculosis or granulomatosis with polyangiitis and was further confounded by negative computed-tomography (CT)-guided biopsy and bronchoscopy findings, which added to the delay in diagnosis. With the currently available knowledge, the diagnosis of PSC depends largely on evaluation of the surgically resected specimen, which in most cases is avoided until there is a high suspicion of PSC. Biopsy is not useful due to extensive necrosis, as will be seen in our case. Consequently, most of the data in the literature is based on case series of autopsy specimen, and the clinical characteristics of PSC remain unclear. The rarity of PSC has prevented its characterization in literature. We report here a rare presentation of PSC with necrotizing lung lesion, to add to the paucity of the current data.

Case presentation and summary

A 58-year-old homeless man presented to the Upstate University Hospital, Syracuse, New York, with a 25-pound weight loss during the previous month and associated productive cough and hemoptysis for a week and a painful mass in the nape of his neck. He denied any fever, chest pain, sick contacts, or joint pain. He had a history of about 40 pack-years of smoking, and his brother had recently been diagnosed with lung cancer. A tender fluctuant mass was detected in the nape of his neck on examination (Figure 1).

The patient had presented 9 months earlier with persistent cough and hemoptysis, and at that visit was found to have a cavitary lesion in the right lung measuring 2 cm (0.8 in). He had undergone a computed-tomograpghy (CT)-guided biopsy of the lesion, which had shown acute and chronic inflammation with fibrosis, and he had negative bronchoscopy findings. The patient tested negative for tuberculosis during the first visit but he left the hospital against the medical advice of the physicians and he was lost to follow-up until his re-presentation.

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On physical examination at his re-presentation, the patient seemed cachectic, with a blood pressure of 94/62 mm of Hg. The mass in the nape of his neck was about 3 cm (1.2 in) long, with erythema of the surrounding skin (Figure 1). Bronchial breath sounds were heard in the right upper lobe of the lung, likely due to the underlying cavitary lesion (Figure 2).

Relevant lab findings included a negative HIV test and repeat AFB (acid-fast bacilli) sputum cultures. A CT-guided biopsy with contrast of the thorax showed an interval increase in the size of the cavitary lesion in the patient’s right upper lobe, now measuring about 10 cm (4 in). Also seen were multiple nodules elsewhere in both lungs, with the largest measuring 8 mm (0.3 in). A CT scan of the neck showed 3 cm cystic mass within the posterior subcutaneous soft tissue of the C3 level, confirming the examination finding of the neck mass (Figure 2) with peripheral enhancement and surrounding infiltrative changes, likely abscess or malignant lymph node versus necrotic infection. He underwent bronchoscopy, which again failed to reveal any endobronchial lesions. Bronchoalveolar lavage was sent for microbiological analysis, including AFB and fungus, but came back negative. Transbronchial biopsy cytology revealed fragments of tumor composed of large pleomorphic cells without glandular or squamous differentiation, within large areas of necrosis (Figure 3).

Immunohistochemical studies showed strong reactivity with cytokeratin CAM5.2 (Figure 4), weak and focal reactivity with cytokeratin AE1/AE3 (Figure 5), and lack of reactivity with CD20, CD3, CD30, S-100, MART-1, TTF-1 and p63, all findings consistent with sarcomatoid carcinoma.

The patient underwent fine-needle aspiration and drainage of the neck lesion and the culture grew mixed organisms. The results of a bone scan, which was done within a week, showed multiple foci of uptake in the ribs and cervical spine.

Given the patient’s advanced disease, he was started on palliative radiotherapy with radiosensitizing chemotherapy with carboplatin (target AUC 6) and paclitaxel (135 mg/m² over 24 hours). His symptoms of hemoptysis improved transiently after the first cycle, but he became hypotensive and drowsy during the second cycle of therapy, and the family decided to make the patient comfort care and withdraw all further treatment. He was discharged to hospice.