The clinical significance of stringent complete response in multiple myeloma is surpassed by minimal residual disease measurements.

BACKGROUND: Stringent complete response (sCR) is used as a deeper response category than complete response (CR) in multiple myeloma (MM) but may be of limited value in the era of minimal residual disease (MRD) testing. METHODS: Here, we used 4-colour multiparametric flow cytometry (MFC) or next-generation sequencing (NGS) of immunoglobulin genes to analyse and compare the prognostic impact of sCR and MRD monitoring. We included 193 treated patients in two institutions achieving CR, for which both bone marrow aspirates and biopsies were available. RESULTS: We found that neither the serum free light chain ratio, clonality by immunohistochemistry (IHC) nor plasma cell bone marrow infiltration identified CR patients at distinct risk. Patients with sCR had slightly longer progression-free survival. Nevertheless, persistent clonal bone marrow disease was detectable using MFC or NGS and was associated with significantly inferior outcomes compared with MRD-negative cases. CONCLUSION: Our results confirm that sCR does not predict a different outcome and indicate that more sensitive techniques are able to identify patients with differing prognoses. We suggest that MRD categories should be implemented over sCR for the future classification of MM responses.

Neuroendocrine tumor of the pancreas in a patient with tuberous sclerosis: a case report and review of the literature.

A rare case of pancreatic neuroendocrine neoplasm in a patient with tuberous sclerosis complex is described. The patient was a 31-year-old man who had multiple congenital subependymal nodules, bilateral cortical tubers, and seizures of difficult control. A 2.3 cm × 2 cm well-delimitated solid tumor in the tail of the pancreas was discovered during a monitoring abdominal computed tomography. A distal pancreatectomy was performed. Histologically, the tumor was formed by uniform cells with moderated cytoplasm arranged in a combined trabecular and nested pattern. The nuclear features were bland, and mitosis was infrequent. There was no vascular invasion. Immunoreactivity for cytokeratine AE1/AE3, chromogranin A, and synaptophysin confirmed the neuroendocrine nature of this neoplasia. Pancreatic hormones were negatives. One of the 5 lymph nodes isolated from the peripancreatic adipose tissue was positive for metastases. Small series and case reports have documented that in tuberous sclerosis many endocrine system alterations might occur, affecting the function of the pituitary, parathyroid, and other neuroendocrine tissue, including islet cells of the pancreas. However, the true association of these pathological conditions remains uncertain. As far as we know, there are 10 cases reported of pancreatic neuroendocrine tumors in a setting of tuberous sclerosis complex, in which 2 cases resulted in malignant, nonfunctioning pancreatic neuroendocrine tumors.