Paraneoplastic hypercalcemia in a patient with adenosquamous cancer of the colon.

Hypercalcemia is a well-known manifestation of paraneoplastic syndromes associated with a variety of malignancies. However, colon cancer has only rarely been associated with hypercalcemia of malignancy. We present the case of a patient with recurrent adenosquamous carcinoma of the ascending colon found to have hypercalcemia. The patient is a 76-year-old white woman who initially presented with colon cancer in the cecum and underwent a right hemicolectomy. All lymph nodes and surgical margins were free of tumor. Pathological examination at that time revealed adenosquamous carcinoma of the colon. Eight months later she complained of dizziness, anorexia, and constipation and was found to have a calcium level of 13.6 mg/dL. CT scan revealed a mass measuring 10.5 to 12.7 cm in the right hepatic lobe, and a bone scan was normal. Her intact parathyroid hormone (PTH) level was 6 pg/mL (normal 12-72) and her PTH-related protein (PTHrP) level was 25.7 pmol/L (normal <1.3). She then underwent a hepatic resection. The serum PTH, calcium, and PTHrP levels normalized after resection. Hypercalcemia of malignancy in colon cancer is rare and has an association with adenosquamous histology. The hypercalcemia is attributed to PTHrP, and here we demonstrate this in the serum and tumor specimens. The effects of PTHrP are shown to be short-lived postoperatively. We find only 14 other cases in the literature of hypercalcemia related to a colonic neoplasm, and this is the only patient reported to be surviving. The diagnosis of a paraneoplastic syndrome mediated via PTHrP should be considered when hypercalcemia is encountered in the setting of metastatic colon carcinoma.     

A case of renal pelvic squamous cell carcinoma accompanied with humoral hypercalcemia of malignancy (HHM)

A 78-year-old male was urgently admitted to our hospital because of consciousness disturbance. Laboratory data showed marked hypercalcemia (17.0 mg/dl), hypophosphatemia, low intact PTH level, high PTH relating peptide (PTHrP) level, normal osteocalcin and normal 1-25(OH)2D level. Computed tomography revealed a right renal tumor with extracapsular extension. Bone scintigram appeared normal. We performed right nephrectomy under the diagnosis of right renal tumor. Pathological diagnosis was poorly differentiated squamous cell carcinoma (SCC) of the right pelvis. Immunohistochemical study of the resected specimen for PTHrP was positive. Therefore, we diagnosed it as renal pelvic SCC with humoral hypercalcemia of malignancy (HHM). After nephrectomy, serum calcium returned to normal, but 5 months after nephrectomy, local recurrence appeared and serum calcium was re-elevated. She died 7 months after nephrectomy.     

Two cases of squamous cell carcinoma of upper urinary tract with hypercalcemia

We report two cases of squamous cell carcinoma of upper urinary tract with hypercalcemia. Case 1; a 54 year old female with primary squamous cell carcinoma (SCC) of right ureter showed marked hypercalcemia and leukocytosis. High levels of serum parathyroid hormone-related peptide (PTHrP) and granulocyte colony stimulating factor (G-CSF) were detected. Although chemotherapy of cisplatin and 5-fluorouracil with radiotherapy was effective, thereafter recurrence was occurred in renal pelvis, and the patient died 17 months after the initiation of therapy. Case 2; a 54 year old male of primary SCC of right renal pelvis with local lymphadenopathy and anterior mediastinal metastases showed marked hypercalcemia. High levels of PTHrP were detected. Although the patient was administered UFT with palliative radiotherapy to the anterior mediastinum, he died 2 months after the initiation of therapy. To our knowledge, the case 1 is the third case that of the high levels of serum PTHrP and G-CSF simultaneously in squamous cell carcinoma of upper urinary tract.     

Pheochromocytoma with hypercalcemia: case report and review of literature

We report a case of severe hypercalcemia and a pheochromocytoma of the right adrenal gland. The patient underwent adrenalectomy, following which the hypercalcemia disappeared. Parathormone assay of the adrenal tumor revealed high levels of activity despite normal serum parathormone activity. This suggests that the etiology of hypercalcemia in patients with pheochromocytoma is related to ectopic secretion of a parathormone ectopic peptide-like substance.     

Parathyroid-hormone-related protein-mediated hypercalcemia in benign congenital mesoblastic nephroma

Parathyroid hormone-related protein (PTHrP) mediated hypercalcemia of malignancy is rare in children, and even more so in the setting of a benign tumor. We report two infants with PTHrP-mediated hypercalcemia secondary to congenital mesoblastic nephroma and their outcome after removal of the benign tumor. Pre-operatively hypercalcemia was corrected with saline hydration, furosemide, calcitonin and/ or pamidronate. Following resection of the tumor serum PTHrP normalized. Immunohistochemical staining of tumor cells was positive for PTHrP. Post-operatively the infants developed elevated serum parathyroid hormone with low- normal serum Ca and P, and undetectable urinary Ca and P, probably due to their movement into bone. Children needed treatment with calcitriol, Ca and P supplementation for 6-12 weeks until PTH normalized and urinary Ca and P were detected, suggesting bone replenishment. We conclude that benign congenital mesoblastic nephroma can secrete PTHrP that can cause severe hypercalcemia; and following excision one should anticipate the development of a transient modified “hungry bone”-like condition requiring Ca, P and calcitriol therapy for several weeks accompanied by careful monitoring of mineral homeostasis.     

A comparison of parathyroid hormone‐related protein (1‐36) and parathyroid hormone (1‐34) on markers of bone turnover and bone density in postmenopausal women: The PrOP study

Parathyroid hormone‐related protein (PTHrP)(1‐36) increases lumbar spine (LS) bone mineral density (BMD), acting as an anabolic agent when injected intermittently, but it has not been directly compared with parathyroid hormone (PTH)(1‐34). We performed a 3‐month randomized, prospective study in 105 postmenopausal women with low bone density or osteoporosis, comparing daily subcutaneous injections of PTHrP(1‐36) to PTH(1‐34). Thirty‐five women were randomized to each of three groups: PTHrP(1‐36) 400 µg/day; PTHrP(1‐36) 600 µg/day; and PTH(1‐34) 20 µg/day. The primary outcome measures were changes in amino‐terminal telopeptides of procollagen 1 (PINP) and carboxy‐terminal telopeptides of collagen 1 (CTX). Secondary measures included safety parameters, 1,25(OH)₂ vitamin D, and BMD. The increase in bone resorption (CTX) by PTH(1‐34) (92%) (p < 0.005) was greater than for PTHrP(1‐36) (30%) (p < 0.05). PTH(1‐34) also increased bone formation (PINP) (171%) (p < 0.0005) more than either dose of PTHrP(1‐36) (46% and 87%). The increase in PINP was earlier (day 15) and greater than the increase in CTX for all three groups. LS BMD increased equivalently in each group (p < 0.05 for all). Total hip (TH) and femoral neck (FN) BMD increased equivalently in each group but were only significant for the two doses of PTHrP(1‐36) (p < 0.05) at the TH and for PTHrP(1‐36) 400 (p < 0.05) at the FN. PTHrP(1‐36) 400 induced mild, transient (day 15) hypercalcemia. PTHrP(1‐36) 600 required a dose reduction for hypercalcemia in three subjects. PTH(1‐34) was not associated with hypercalcemia. Each peptide induced a marked biphasic increase in 1,25(OH)₂D. Adverse events (AE) were similar among the three groups. This study demonstrates that PTHrP(1‐36) and PTH(1‐34) cause similar increases in LS BMD. PTHrP(1‐36) also increased hip BMD. PTH(1‐34) induced greater changes in bone turnover than PTHrP(1‐36). PTHrP(1‐36) was associated with mild transient hypercalcemia. Longer‐term studies using lower doses of PTHrP(1‐36) are needed to define both the optimal dose and full clinical benefits of PTHrP. © 2013 American Society for Bone and Mineral Research. © 2013 American Society for Bone and Mineral Research.     

PTHrP(12‐48) Modulates the Bone Marrow Microenvironment and Suppresses Human Osteoclast Differentiation and Lifespan

Bone is a common site for metastasis in breast cancer patients and is associated with a series of complications that significantly compromise patient survival, partially due to the advanced stage of disease at the time of detection. Currently, no clinically‐approved biomarkers can identify or predict the development of bone metastasis. We recently identified a unique peptide fragment of parathyroid hormone‐related protein (PTHrP), PTHrP(12‐48), as a validated serum biomarker in breast cancer patients that correlates with and predicts the presence of bone metastases. In this study, the biological activity and mode of action of PTHrP(12‐48) was investigated. Sequence‐based and structure‐based bioinformatics techniques predicted that the PTHrP(12‐48) fragment formed an alpha helical core followed by an unstructured region after residue 40 or 42. Thereafter, detailed structure alignment and molecular docking simulations predicted a lack of interaction between PTHrP(12‐48) and the cognate PTH1 receptor (PTHR1). The in silico prediction was confirmed by the lack of PTHrP(12‐48)‐stimulated cAMP accumulation in PTHR1‐expressing human SaOS2 cells. Using a specific human PTHrP(12‐48) antibody that we developed, PTHrP(12‐48) was immunolocalized in primary and bone metastatic human breast cancer cells, as well as within human osteoclasts (OCLs) in bone metastasis biopsies, with little or no localization in other resident bone or bone marrow cells. In vitro, PTHrP(12‐48) was internalized into cultured primary human OCLs and their precursors within 60 min. Interestingly, PTHrP(12‐48) treatment dose‐dependently suppressed osteoclastogenesis, via the induction of apoptosis in both OCL precursors as well as in mature OCLs, as measured by the activation of cleaved caspase 3. Collectively, these data suggest that PTHrP(12‐48) is a bioactive breast cancer–derived peptide that locally regulates the differentiation of hematopoietic cells and the activity of osteoclasts within the tumor–bone marrow microenvironment, perhaps to facilitate tumor control of bone. © 2017 American Society for Bone and Mineral Research.     

Hypercalcemia associated with parathyroid hormone-related protein at the terminal stage of uncomplicated squamous cell carcinoma in the head and neck region.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) is mainly responsible for hypercalcemia in squamous cell carcinomas (SCCs). METHODS: We retrospectively checked the appearance of hypercalcemia among 33 patients who died with head and neck SCC. Serum concentrations of C-terminal region of PTHrP (C-PTHrP) were measured in 15 of them. The intracellular PTHrP expression was immunohistochemically stained in 42 SCC sections obtained from the 33 before the appearance of hypercalcemia. RESULTS: Hypercalcemia appeared in 24 of the 33, and increased serum C-PTHrP levels were confirmed in 11 of 12 hypercalcemic patients. PTHrP was identified in all SCC sections, and a stronger intensity than in normal squamous epithelia was observed in 50% of those obtained within 1 year before the onset of hypercalcemia. CONCLUSION: A high incidence of PTHrP-induced hypercalcemia was shown among patients dying with head and neck SCCs. The intracellular increase in PTHrP might be observed preceding hypercalcemia.     

A case of renal pelvic squamous cell carcinoma accompanied with humoral hypercalcemia of malignancy

A 74-year-old male was urgently admitted to our hospital because of consciousness disturbance. Laboratory data showed remarkable hypercalcemia (7.8 mEq/L), hypophosphatemia, low % TRP, low intact PTH level, normal nephrogenic cyclic AMP and normal 1,25 (OH)2D level. Serum bone Gla protein, which was thought to express osteoblastic activity, was low. Serum tartarate resistant acid phosphatase and urinary excretion of hydroxyproline, which were thought to express osteoclastic activity, were high. CT scan showed an enlarged mass in the left renal pelvis, which was found to be a squamous cell carcinoma (SCC) by biopsy through percutaneous nephroscopy. Bone scintigram appeared normal. Therefore, we diagnosed it as renal pelvic SCC with humoral hypercalcemia of malignancy (HHM) and performed left nephrectomy. After nephrectomy, serum calcium returned to normal. But after a few weeks, lung metastasis appeared and serum calcium was reelevated. As to PTH related protein (PTHrP) which was thought to induce HHM, PTHrP content of the resected tumor measured by RIA assay was 13 pmol/g wet weight of tissue, which suggested that this tumor might have been producing PTHrP.     

A 7‐day continuous infusion of PTH or PTHrP suppresses bone formation and uncouples bone turnover

Human in vivo models of primary hyperparathyroidism (HPT), humoral hypercalcemia of malignancy (HHM), or lactational bone mobilization for more than 48 hours have not been described previously. We therefore developed 7‐day continuous‐infusion models using human parathyroid hormone(1–34) [hPTH(1–34)] and human parathyroid hormone–related protein(1–36) [hPTHrP(1–36)] in healthy human adult volunteers. Study subjects developed sustained mild increases in serum calcium (10.0 mg/dL), with marked suppression of endogenous PTH(1–84). The maximal tolerated infused doses over a 7‐day period (2 and 4 pmol/kg/h for PTH and PTHrP, respectively) were far lower than in prior, briefer human studies (8 to 28 pmol/kg/h). In contrast to prior reports using higher PTH and PTHrP doses, both 1,25‐dihydroxyvitamin D₃ [1,25(OH)₂D₃] and tubular maximum for phosphorus (TmP/GFR) remained unaltered with these low doses despite achievement of hypercalcemia and hypercalciuria. As expected, bone resorption increased rapidly and reversed promptly with cessation of the infusion. However, in contrast to events in primary HPT, bone formation was suppressed by 30% to 40% for the 7 days of the infusions. With cessation of PTH and PTHrP infusion, bone‐formation markers abruptly rebounded upward, confirming that bone formation is suppressed by continuous PTH or PTHrP infusion. These studies demonstrate that continuous exposure of the human skeleton to PTH or PTHrP in vivo recruits and activates the bone‐resorption program but causes sustained arrest in the osteoblast maturation program. These events would most closely mimic and model events in HHM. Although not a perfect model for lactation, the increase in resorption and the rebound increase in formation with cessation of the infusions are reminiscent of the maternal skeletal calcium mobilization and reversal that occur following lactation. The findings also highlight similarities and differences between the model and HPT. © 2011 American Society for Bone and Mineral Research     

Hypercalcemia in a patient with renal cell carcinoma producing parathyroid hormone-related protein and interleukin-6

A patient with renal cell carcinoma who developed humoral hypercalcemia of malignancy is reported. A 52-year-old male patient was diagnosed with renal cell carcinoma and multiple lung metastases. A cell line isolated from the surgical specimen exhibited continuous production of parathyroid hormone-related protein (PTHrP) in vitro. The production of PTHrP from the cancer cells was confirmed by RT-PCR and immunoradiometric assay. The serum calcium level was not enhanced, whereas the lung lesion was developing and producing interleukin-6, a possible modulator of osteoclastic resorption. Hypercalcemia was induced when the PTHrP concentration increased up to 3.3 pmol/L.     

PTHrP, calcitonin and calcitriol in a case of severe, protracted and refractory hypercalcemia due to a pancreatic neuroendocrine tumor

A patient with a primary neuroendocrine tumor of the pancreas, presented with severe hypercalcemia. This hypercalcemia of malignancy (HCM) failed to respond to intensive bisphosphonate treatment and needed continuous enhanced diuresis. Only after successful antitumor therapy did the hypercalcemia subside. Hypercalcemia was associated with increased concentrations of plasma PTHrP, calcitonin and 1,25-(OH)(2)D(3). Bone mineral density was markedly increased. We demonstrated the presence of both PTHrP and calcitonin in the tumor at the mRNA and protein level, using RT-PCR, immunohistochemistry and Western blotting. The high levels of plasma PTHrP and the demonstrated predominant renal mechanism in this case of HCM are suspected to be the cause for its refractoriness to bone resorption inhibitors. Our findings furthermore suggest that the tumoral production of calcitonin and PTHrP might have contributed to the increased bone mineral storage of calcium and thus probably attenuated the development of frank hypercalcemia.     

Penile carcinoma with humoral hypercalcemia of malignancy (HHM): a case report]

A 57-year-old male, with 1.5 cm tumor in his prepuce, was admitted to our institute in Feb. 1990. Circumcision and inguinal lymph node dissection was performed under the diagnosis of T1 disease of penile carcinoma. Pathological evaluation revealed well-differentiated squamous cell carcinoma (SCC). In April 1996, the patient revealed recurrence of the disease in the right inguinal lymph nodes and the lower abdomen, that was diagnosed to be poorly differentiated SCC. Laboratory findings showed elevation of serum calcium, parathyroid hormone-related protein (PTHrP) levels. Immunohistochemical staining confirmed production of PTHrP in the tumor tissue. This is the first case report of penile carcinoma that caused humoral hypercalcemia of malignancy in Japan.     

Hypercalcemia upon recurrence of renal cell carcinoma producing parathyroid hormone-related protein

We established a new renal carcinoma cell line that produces parathyroid hormone-related protein (PTHrP) and interleukin-6 in culture. The cellular production of PTHrP was confirmed by Northern blot analysis and immunofluorescence examination. Bone and lung metastases occurred simultaneously 3.5 years after surgery. The patient did not show hypercalcemia at this time, despite the presence of multiple osteolytic metastases. About 7 months after bone metastasis was first shown, serum PTHrP was detected by means of an immunoradiometric assay and the calcium level was found to be elevated to 3.29 mmol/l. The hypercalcemia was successfully controlled by i.v. administration of bisphosphonates.     

Simultaneous production of granulocyte colony-stimulating factor and parathyroid hormone-related protein in bladder cancer

A case of bladder cancer with simultaneous production of granulocyte colony-stimulating factor (G-CSF) and parathyroid hormone-related protein (PTHrP) is reported. An 81-year-old male patient was admitted to the Saitama Medical School for treatment of gross hematuria, leukocytosis and hypercalcemia and diagnosed as having advanced bladder cancer. Immediately after a cystectomy was carried out, his white cell count and serum calcium levels returned to normal. However, the tumors recurred locally and the recurrence was accompanied by an increase in the serum G-CSF and PTHrP levels with a recurrent elevation of white cell count and the serum calcium level. The production of G-CSF and PTHrP in the tumor cells was confirmed by immunohistochemistry.     

Humoral Hypercalcemia Complicating Adenocarcinoma of the Sigmoid Colon: Report of a Case

Humoral hypercalcemia can arise from a variety of malignancies, but its association with primary colorectal carcinoma is rare, with only 20 such cases documented in the English-language literature to date. We report an additional case to clarify the clinicopathologic features of colorectal carcinoma with humoral hypercalcemia. A 54-year-old woman was admitted with symptomatic hypercalcemia of 14.2 mg/dl and multiple hepatic metastases, 2 years after resection of sigmoid colon cancer. The hypercalcemia was caused by the circulating parathyroid hormone-related peptide (PTHrP) produced by poorly differentiated adenocarcinoma in the liver. The PTHrP level on admission was 13.5 pmol/l. Despite systemic chemotherapy, the patient died of disease progression 3 weeks after the humoral hypercalcemia was diagnosed. A review of the 21 reported cases, including ours, suggests that colorectal carcinoma associated with humoral hypercalcemia is characterized by a poorly differentiated tumor with or without squamous or neuroendocrine features, distant metastases, and a dismal prognosis.     

Pancreatic neuroendocrine cell tumor secreting parathyroid hormone-related protein and gastrin: Report of a case

This report presents a case of pancreatic neuroendocrine cell carcinoma with multiple liver metastases secreting gastrin and parathyroid hormone-related protein (PTHrP) related to lumbar bone fracture and hypercalcemia. A 58-year-old woman visited an affiliated hospital with a chief complaint of lumbago without any evidence of trauma. She was diagnosed with hepatic dysfunction and hypercalcemia as well as multiple lumbar compression fractures without osteolytic lesions. Abdominal computed tomography (CT) showed a hypervascular mass in the pancreatic tail and multiple liver tumors. Duodenal ulcers were found with gastrointestinal endoscopy. There was a marked increase in the serum gastrin level. She was diagnosed as gastrinoma with multiple liver metastases and was admitted to the hospital. She had an increase in serum PTHrP level without the elevation of intact parathyroid hormone at the time of admission. She underwent an extended right hepatectomy in addition to a distal pancreatectomy with a regional lymphadenectomy and splenectomy. The postoperative course was uneventful, and serum gastrin and PTHrP activities reduced to normal levels. She remained symptom-free, and serum calcium, gastrin, and PTHrP levels remain within the normal ranges 19 months after surgery without adjuvant therapy.     

Parathyroid hormone-related peptide as a cause of hypercalcemia in squamous cell carcinoma of the head and neck: a case presentation and subject review

BACKGROUND: Serum levels of parathyroid hormone-related peptide (PTHrP) can be elevated with malignancy and cause hypercalcemia, which has been associated with a poor prognosis. METHODS: We present a case of supraglottic squamous cell carcinoma with elevated serum PTHrP and hypercalcemia. The patient was acutely managed with intravenous fluids, furosemide, and zoledronic acid and then underwent a total laryngectomy and modified radical neck dissection. RESULTS.: The patient remains disease free and normocalcemic. CONCLUSION: Curative treatment for patients with head and neck cancer should not be withheld solely on the basis of humoral hypecalcemia of malignancy.     

Parathyroid hormone-related protein induced coupled increases in bone formation and resorption markers for 7 years in a patient with malignant islet cell tumors.

Parathyroid hormone-related protein (PTHrP) and PTH share the common PTH/PTHrP receptor. Although an elevated level of circulating PTHrP in patients with malignancies causes hypercalcemia as does PTH, chronic and systemic effects of PTHrP on bone metabolism in humans are not well understood because tumor-burden patients showing hypercalcemia usually have a poor prognosis. We investigated bone and calcium metabolism in a patient with malignant islet cell tumors showing hypercalcemia due to the elevated plasma PTHrP level for 7 years. Hypercalcemia and hypercalciuria continued throughout the clinical course in spite of frequent infusions of bisphosphonates. Bone resorption markers and a bone formation marker were consistently elevated as seen in primary hyperparathyroidism, a disease caused by an autonomous hypersecretion of PTH. Based on biochemical measurements including bone markers and serum 1,25-dihydroxyvitamin D, the clinical features of this case essentially are the same as those of primary hyperparathyroidism except for the elevated level of plasma PTHrP with suppressed intact PTH level. Therefore, it is suggested that chronic and systemic effects of PTHrP on bone as well as calcium metabolism are indistinguishable from those of PTH in human.