Everolimus in poorly differentiated neuroendocrine carcinoma of unknown primary: A case report

Abstract

Malignancies with unknown primaries contribute to a small yet significant percentage of overall tumors. Neuroendocrine carcinomas, a rare disease with a poor prognosis, have been known to present as an unknown primary. Treatment consists of cytotoxic chemotherapy but given the latter's high toxicity profile new treatment options are being explored. In this case report, we describe a case of a patient with poorly differentiated neuroendocrine carcinoma of unknown primary treated with compassionate oral everolimus after his refusal of intravenous chemotherapy.

Keywords: Everolimus; hematology; oncology; poorly differentiated neuroendocrine carcinoma.

Figure 1.

Coronal scans of the adrenals (1), inguinal region (2), pelvic area (3), portocaval (4), axillary (5), hilar (6), and peri-psoas muscle areas (7). Sagittal scan of the cervical area (8).

Figure 2.

I(a): CD56 ×100; Positive membranous staining. I(b): CK7 ×400; Positive cytoplasmic staining of tumor cells with characteristic perinuclear dots. I(c): TTF1 ×100; Positive nuclear staining. I(d): Synaptophysin ×100; Positive cytoplasmic staining. II(a): HE ×100; The tumor cells are arranged in nests of variable size and shape, some of which exhibiting peripheral nuclear palisading, set within a desmoplastic stroma. II(b): HE ×400; Mitotic figures are also easily detected. II(c): HE ×400; Tumor cells have high nuclear to cytoplasmic ratio and exhibit an oval to round nucleus with finely granular chromatin. Occasional necrotic areas are present (left upper area). II(c): HE ×40; Sheets of metastatic small cell carcinoma cells (left lower half) in a lymph node (residual lymphocytes at the periphery).

Figure 3.

Ki-67 immunohistochemical stain revealing expression by approximately 80% of the neoplastic cells. Original magnification 200×.

Figure 4.

Initial (left) FDG-PET showing increased uptake in several organs versus mild progress seen in a comparable image 6 months later (right).