Identification of the genetic aetiologies of hypoparathyroidism makes it possible to predict patient outcomes and provide appropriate genetic counselling. Long-term treatment with calcium and calcitriol necessitates monitoring for renal complications.

BACKGROUND Up to the current time, diagnosis of bone marrow (BM) involvement in non‐Hodgkin lymphoma (NHL) has been based on morphologic findings. Polymerase chain reaction (PCR) for antigen receptor gene rearrangements has the potential to increase the detection sensitivity of minimal degrees of BM involvement. The authors therefore assessed PCR‐based clonalities of BM concurrently with morphology from 170 cases with NHL and evaluated the usefulness of comparative analysis of clonalities between bilateral BMs and the lymph node and the clinical significance of PCR based clonalities of BM. METHODS Bilateral BM clot sections of 170 cases and 47 lymph nodes were tested for immunoglobulin heavy chain gene rearrangement or T‐cell receptor gamma gene rearrangement according to the B‐ or T‐lineage of the lymph node. RESULTS When compared with morphology, the results of PCR showed an unexpectedly low positive concordance rate of 61.0% for B‐cell NHL and 57.1% for T‐cell NHL. When the clonality of BM was compared with that of lymph nodes in B‐cell NHL, bilateral clonalities of BM showed high concordance with the clonality of the lymph nodes. PCR‐based clonality did not show significant impact on survival. CONCLUSIONS Morphology remains the gold standard in the evaluation of BM involvement by NHL. Although the comparative analysis of BM clonality and that of the lymph nodes is considered a valuable tool that increases the reliability of clonality, PCR‐based clonality of BM does not significantly add to the sensitivity of diagnosing BM involvement by NHL. Cancer 2002;94:3073–82. © 2002 American Cancer Society. DOI 10.1002/cncr.10584