64-year-old presented to the emergency room complaining of dizziness and confusion for two months prior to presentation. Patient then developed altered mental status and he was brought to the ER. The patient denied any focal neurological deficits. On admission to the hospital, his vital signs were stable, his physical exam was negative including for focal neurological deficits, and laboratory data were unrevealing. CT scan of the head revealed left basal ganglia mass with associated vasogenic edema and obstructive hydrocephalus. He was given Decadron and Keppra for vasogenic edema and seizure prophylaxis respectively. MRI of the head showed multiple enhancing lesions with concern for obstructive hydrocephalus. Further metastasis work up included CT chest, abdomen and pelvis, which was remarkable for large right upper lobe mass and mass-like lesion in the anterior gastric wall. Patient underwent EGD with biopsy of the gastric mass. He also underwent CT-guided needle biopsy of the right lung mass. Patient urgently received whole brain radiation for obstructive hydrocephalus, and his condition remained stable throughout the hospital course. Upon discharge case was felt to be most consistent with adenocarcinoma given organ involvement. Biopsy of the RUL mass was initially read as necrotic malignant non-small cell carcinoma, with no characterization possible due to extensive necrosis. Patient was discharged home with close outpatient follow up without any definitive diagnosis. The gastric biopsy returned as malignant melanoma and the lung biopsy was re-read as melanoma. The results of the biopsies were relayed to the patient. Patient opted for hospice.
Discussion:
This case explored the utility of multiple biopsy sites when primary tumor is unclear at the time of presentation to provide confirmatory results when biopsies have poor yield. CT-guided lung biospsies when FNA and Core are combined have 95% diagnostic accuracy. In that 5% additional biopsy are required of other sites. In our patient with a gastric and lung solitary lesion in the context that adenocarcinoma comprises 70% of cancers of unknown origin, it was imperative that both biopsies be taken in an attempt to guide treatment. In the setting of two solitary lesions there was concern that the patient may have two primary tumors and given the accessibility of both lesions for biopsy decision was made to proceed with both. For our case the gastric biopsy confirmed the lung biopsy which was necrotic and initially read as non-small cell. We were able to have both biopsies performed early in the course and since patient was stable during his stay he was discharged.
This case was complicated by the patient’s clear desire for hospice if he was found to have a diagnosis with poor outcomes. He was diagnosed with stage IV melanoma with metastasis to the brain and involvement of gastrointestinal tract, which holds a poor prognosis. Patients with CNS involvement have the smallest overall average survival of 2.5 months. Our decision to delay diagnosis despite initial biopsies consistent with our thought that this was metastatic adenocarcinoma was prudent as initial biopsy was confounded by necrosis and described as non-small cell and he was definitively found to have melanoma.
Conclusions:
Biopsying multiple sites in metastatic cancer on presentation help to decrease length of stay and provide patients a more timely and accurate diagnosis to help decrease diagnosis anxiety and help make treatment decisions.