In 2009, a 42-year-old non-smoking male presented to our hospital for the evaluation of a right lung nodule detected during physical examination. He underwent radical resection of the right lung, and the postoperative pathological report revealed a mucoid adenocarcinoma of the inferior lobe of the right lung (3.5 × 3.0 cm), but no positive lymph nodes (0 of 29; T2aN0M0 stage I). The patient relapsed in 2015. A computed tomography (CT) scan revealed a mass in the superior lobe of the right lung and mediastinal lymph node enlargement. He underwent resection of the residual right lung. Postoperative pathological evaluation and hematoxylin and eosin staining showed different histomorphologies in the primary lung site (mucinous type) (Fig a) and the fourth group of lymph node metastases (solid type, T2N2M0 stage III) (Fig b). Immunohistochemistry indicated a pulmonary origin of both tumors: TTF-1 and Napsin A were positive, and CK 5/6 and P63 were negative. We simultaneously detected ALK and EGFR gene status by reverse transcription-PCR (Amoy, Xiamen, China) in two tumor tissue specimens. The results indicated a positive EML4-ALK rearrangement in tissues and wild EGFR (Fig ). The patient received adjuvant chemotherapy and achieved stable disease.
A 49-year-old male was presented at our department with lower back pain and walking instability for the last few days. The patient suffered from end-stage renal disease on dialysis for the last 15 years and had a history of successful renal transplantation about 25 years ago. The initial renal insufficiency resulted from a chronic glomerulonephritis and the allograft was rejected 9 years after transplantation due to the same underlying condition. Furthermore, about 2 years ago, he underwent bilateral nephrectomy for solid tumorous masses in both nonfunctioning kidneys. The histologic examination revealed, bilaterally at that time, type 1 papillary renal cell carcinoma (pT1aN0M0, Fuhrman grade II, in sano resection). Additionally, the nonfunctioning transplant kidney was removed about 6 months ago due to recurrent episodes of macrohaematuria, without evidence for a malign tumour. At that time, there were no signs for a metastatic disease.\nAt current presentation, the performed magnetic resonance imaging (MRI) of the spine showed a pathologic facture at the right side of the first and second lumbar vertebral body () from a metastatic solid mass, as well as multiple osteolytic metastases from 7th cervical to 2nd lumbar vertebra. A staging computed tomography (CT) of the thorax and abdomen showed further osseous osteolytic metastatic lesions at the sternum, both scapulae, the bone pelvis, and the left proximal femoral bone. The performed biopsy of the osteolytic metastatic lesion at the second lumbar vertebra revealed a metastatic, mucin-poor variant, of a mucinous tubular and spindle cell carcinoma of the kidney (). A thorough reexamination of the old nephrectomy specimens showed that the tumour of the right kidney was also a mucin-poor variant of a MTSCC of the kidney, while the tumour of the left kidney was confirmed as a papillary RCC.\nHistologically, both the biopsy sample and the nephrectomy-specimen of the right kidney showed a renal cell tumour with a spindle cell component, as well as tubular and papillary parts without any clear cells. Both spindle and tubular-papillary parts were delimited by a basal membrane, forming a ball-shaped, epithelial tumour-growth pattern with spindled nuclear morphology, which did not match a sarcomatoid differentiation. Immunohistochemically, the tumour was negative for desmin and actin and S100 protein, as well as for HMB45, MITF1, MART1, and SOX-10. A positive reaction to Racemase (AMARC), PAX-8, and RCC was found, with focal positivity for CD10. Pan-Cytokeratin (AE1/AE3) and CK7 were negative except from the papillary parts. The Ki67 stain showed focal proliferation rates up to 30%. Furthermore, no mucoid interstitial matrix was found with H&E stain. Only with Alcian blue staining, <1% mucin in cellular areas was observed.\nAccording to our interdisciplinary tumour conference board's recommendation, the patient followed a systemic treatment with pazopanib and focal radiotherapy to lumbar and cervical vertebrae metastases. In further follow-up, irrespective of the started treatment, the tumour spread rapidly and after three months the patient presented with additional hepatic and pulmonary metastases. The patient finally succumbed to the disease a few months later.