Metastatic Clear Cell Carcinoma of Unknown Primary Origin in an Elderly Female Patient With Paraneoplastic Hypercalcemia

Metastatic clear cell carcinoma (mCCC) is a rare histological subtype of cancer with ovarian and renal origins most common primary sites. Cancer of unknown primary origin (CUP) is a rare type of cancer in the United States and the most common histologic subtypes are adenocarcinoma, squamous cell cancer, and neuroendocrine cancer. We are presenting a rare case of an 86-year-old female patient with mCCC of unknown origin, biopsy and staining showed renal and ovarian in the differential of primary cancer type. However, the patient did not survive the aggressive nature of mCCC and was unable to get any trials of chemotherapy. Primary sites of adenocarcinoma of unknown origin are most common in the breast, lung, pancreas, prostate, colon, and liver. In most cases, empiric chemotherapy with platinum-based agents is the standard of care but needs more data to manage CUP, making it difficult to identify the primary site.

Delayed Presentation of Air Embolism Within Cerebral Arteries Following Computed Tomography-Guided Lung Biopsy

Computed tomography (CT)-guided percutaneous core needle biopsy of the lung is a frequently performed interventional radiological procedure. Most complications are minor and self-resolving. However, a rare but potentially fatal complication is that of systemic air embolism, especially when to the cerebral or coronary arteries. This study reports a case of delayed (12 hours after initial biopsy) air embolism in the cerebral arteries that resulted from an otherwise uncomplicated biopsy of a lung nodule. It is vital for early diagnostic confirmation and appropriate treatment if possible, though maximal efforts at prevention are still recommended.

Pembrolizumab-Induced Lichenoid Dermatitis in a Patient With Metastatic Cancer of Unknown Primary

Pembrolizumab is an immune checkpoint inhibitor approved for use in many cancer types such as non-small cell lung cancer (NSCLC), metastatic melanoma, head and neck cancers, hepatocellular carcinoma, and renal cell carcinoma. There are many reported cases of patients on immunotherapy who have discontinued treatment due to the development of immune-related adverse effects (irAE). Recognition of the histopathologic patterns of dermatologic toxicities due to immunotherapy will become increasingly important for ensuring appropriate management and optimal patient care. Here, we present a case of a 72-year-old man with metastatic carcinoma of unknown primary origin treated with pembrolizumab who developed an immune-related cutaneous adverse event (ircAE) in the form of lichenoid dermatitis.