Humoral hypercalcemia in patients with colorectal carcinoma: report of two cases and review of the literature.
BACKGROUND
Humoral hypercalcemia rarely is associated with colorectal carcinoma; to the authors' knowledge only nine cases have been reported to date.


METHODS
Two cases of advanced colorectal carcinoma with humoral hypercalcemia of malignancy (HHM) are presented.


RESULTS
The two patients had severe hypercalcemia without bone metastases. The diagnosis of HHM was based on findings of hypercalcemia, hypophosphoremia, elevated serum parathyroid hormone-related peptide (PTHrP), and positive tumor immunoreactivity to monoclonal PTHrP antiserum. One patient had a colonic adenocarcinoma with a neuroendocrine component and the other patient had rectal adenocarcinoma. Immunoreactive PTHrP was found in both tumor components. Bisphosphonate treatment normalized the hypercalcemia within a few days but it recurred in the patients 2 weeks and 3 weeks later, respectively. The prognosis was extremely poor.


CONCLUSIONS
To the authors' knowledge the two cases presented in the current study are the first to be reported with HHM-associated colorectal carcinoma with positive tumor immunoreactivity to PTHrP monoclonal antiserum.
Lortholary
A H
AH
Department of Medical Oncology, Centre Paul Papin, Angers, France.
Cadeau
S D
SD
Bertrand
G M
GM
Guerin-Meyer
V I
VI
Gamelin
E C
EC
Audran
M J
MJ
D000230:Adenocarcinoma / Q000150:complications* / Q000473:pathology; D000911:Antibodies, Monoclonal; D003110:Colonic Neoplasms / Q000150:complications* / Q000473:pathology; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000209:etiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins / Q000032:analysis / Q000276:immunology; D012004:Rectal Neoplasms / Q000150:complications* / Q000473:pathology
D000911:Antibodies, Monoclonal; C470121:PTHLH protein, human; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins