Neuroendocrine Carcinoma of Unknown Primary Site

Multiple Metastatic Small Cell Carcinoma of Unknown Primary Diagnosed on Inguinal Node Biopsy

“…Patients with small cell carcinoma at a metastatic site are considered for systemic therapy at the time of diagnosis. Although the optimum regimen is undefined, a platinum/etoposide-based regimen is currently used [7]. In this case report, we describe an uncommon case of inguinal lymph node small cell metastasis of unknown origin, accompanied by multiple sites of involvement.…”

Ga-68 DOTANOC PET/CT imaging in detection of primary site in patients with metastatic neuroendocrine tumours of unknown origin and its impact on clinical decision making: experience from a tertiary care centre in India

“…Even in cases, where it is unable to detect the primary site, it provides useful information for guiding clinical management of such patients. Tumor grade/differentiation status currently is an important determinant of the personalized management of these patients (8).…”

“…Often the primary site is small, occult with possibility of multiple and variable primary sites which makes their evaluation difficult (7). Patients with metastatic NETs and unknown primary site (CUP-NET) constitute less than 5% of overall carcinomas of unknown primary (CUP) population (8). However, they constitute 10-13% of total NET study populations (9,10).…”

Cancer of Unknown Primary: The Pathologist’s Approach

“…Squamous cell carcinomas are usually negative for cytokeratins 7 and 20 -two cytokeratins that are often expressed by adenocarcinomas. Among others, determination of neuroendocrine lineage is achieved by the detection of the very specifi c antigens chromogranin A and synaptophysin as well as CD56 (neural cell adhesion molecule, N-CAM), which is very sensitive but less specifi c than the two aforementioned markers [ 17 ]. A fourth antigen indicating neuroendocrine differentiation, NSE (neuron-specifi c enolase), is a very sensitive but even less specifi c marker, so that its diagnostic utility and signifi cance are rather limited.…”