The page contains one full NUR 315 Module 6 case study on hypercalcemia of malignancy, with case presentation, calcium physiology, the feedback loop that sustains it, a findings table, treatment by mechanism, nursing priorities and APA 7 references. Searches like "nur 315 module 6 assignment", "nur315 module 6 case study" and "nur 315 module 6 example" land here.
The NUR 315 Module 6 example, in full
A Hormone Borrowed by a Tumor: A Case Study of Hypercalcemia of Malignancy
[Student Name]
Southern New Hampshire University
NUR 315: Pathophysiology for Nurses
Module Six Case Study
[Instructor Name]
[Date]
The organization, setting and figures below are a composite written as a model document. No real employer, client, colleague or patient is described.
A Hormone Borrowed by a Tumor: A Case Study of Hypercalcemia of Malignancy
Case Presentation
A 64-year-old woman with squamous cell carcinoma of the lung, diagnosed four months earlier and receiving chemotherapy, arrived at the emergency department with her daughter, who had noticed the change. Over the previous week she had become increasingly tired, thirsty and forgetful, was passing large amounts of urine, and her bowels had not moved since the previous weekend. On examination she was drowsy but arousable and oriented only to person. Her mucous membranes were dry, blood pressure was 104/62 mmHg lying down and fell further when she sat up, and pulse was 108 beats per minute.
Laboratory results showed a total serum calcium of 13.8 mg/dL (reference about 8.5 to 10.5) with a normal albumin, a creatinine of 1.7 mg/dL compared with 0.8 mg/dL a month earlier, and a low phosphate. Parathyroid hormone was suppressed, and parathyroid hormone-related protein was elevated. An electrocardiogram showed a shortened QT interval. Imaging did not show bone metastases. She was diagnosed with humoral hypercalcemia of malignancy with acute kidney injury.
Normal Calcium Regulation
Serum calcium is held within a narrow range because it controls nerve and muscle excitability, cardiac conduction and blood clotting. When calcium falls, the parathyroid glands release parathyroid hormone. The hormone raises calcium in three ways: it stimulates bone resorption, releasing calcium from the skeleton; it increases calcium reabsorption in the distal tubules of the kidney while promoting phosphate excretion; and it increases activation of vitamin D, which raises calcium absorption from the gut. When calcium rises, parathyroid hormone secretion falls, and the kidney excretes more calcium (Rogers, 2023).
This feedback loop is why the suppressed parathyroid hormone in this case is informative. The glands are responding correctly to high calcium by switching off. Something outside the loop must be raising calcium despite that signal.
How the Tumor Raises Calcium
Some cancers, most often squamous cell carcinomas of the lung, head and neck, as well as some breast and kidney cancers, secrete parathyroid hormone-related protein. This protein shares a similar structure with parathyroid hormone at the end that binds the receptor, so it activates the same receptor on bone and kidney cells. Unlike parathyroid hormone, its secretion is not switched off by high calcium, so the tumor keeps stimulating calcium release no matter how high the level climbs (Guise & Wysolmerski, 2022).
At bone, the protein increases osteoclast activity, releasing calcium into the blood. At the kidney, it increases calcium reabsorption and phosphate excretion, which explains this patient's low phosphate. This mechanism, called humoral hypercalcemia of malignancy, accounts for most cases of cancer-associated hypercalcemia. Other mechanisms, such as local bone destruction by metastases or tumor production of activated vitamin D, are less likely here because imaging showed no bone lesions (Stewart, 2005).
The Kidney Cycle That Sustains It
Once calcium is high, the kidney itself becomes part of the problem. High calcium impairs the kidney's ability to respond to antidiuretic hormone and concentrate urine, a form of nephrogenic diabetes insipidus. The patient therefore passes large volumes of dilute urine, explaining her polyuria and thirst. Combined with nausea and poor intake, the water loss leads to dehydration, shown by her dry mucous membranes, low blood pressure and fast pulse.
Dehydration lowers blood flow to the kidneys and the glomerular filtration rate, reflected in the creatinine that has more than doubled. With less filtration, the kidneys excrete less calcium, so calcium rises further. High calcium also constricts the renal arteries, reducing filtration more. The result is a self-reinforcing cycle in which high calcium causes dehydration, dehydration reduces kidney function, and reduced kidney function keeps calcium high. Breaking this cycle is the first goal of treatment.
Linking Findings to Mechanisms
Each feature of the case can now be traced to its cause.
Table 1
Findings in the Case and Their Mechanisms
| Finding | Mechanism |
|---|---|
| Calcium 13.8 mg/dL with low parathyroid hormone | Tumor hormone drives bone resorption and renal reabsorption outside normal feedback |
| Low phosphate | Hormone effect increasing kidney phosphate excretion |
| Polyuria and thirst | High calcium blocks urine concentration |
| Low blood pressure, fast pulse, dry mouth | Volume depletion from water loss and poor intake |
| Creatinine 1.7 from 0.8 mg/dL | Reduced kidney blood flow and filtration from dehydration and vasoconstriction |
| Confusion and drowsiness | High calcium reduces nerve excitability in the brain |
| Constipation | Reduced smooth muscle activity in the gut |
| Short QT interval | Faster repolarization of heart muscle cells |
How Treatment Interrupts the Mechanism
Each treatment acts on a specific step. Intravenous isotonic saline restores volume, improves kidney blood flow and increases calcium excretion, breaking the kidney cycle. Calcitonin lowers calcium within hours by reducing bone resorption and increasing renal excretion, but its effect fades within a few days. Intravenous bisphosphonates such as zoledronic acid inhibit osteoclasts and provide a slower but more lasting reduction, and denosumab, which blocks a signal osteoclasts need to form and function, is an option when bisphosphonates cannot be used, including in some patients with reduced kidney function (Guise & Wysolmerski, 2022). Loop diuretics are no longer routine and are used only when fluid overload develops, since they can worsen dehydration. Ultimately, calcium control depends on treating the cancer that produces the hormone, which is why hypercalcemia of malignancy often signals advanced disease.
Nursing Priorities
The mechanisms guide nursing care. Close measurement of intake, output and daily weight shows whether hydration is restoring kidney function, while lung sounds and edema are watched for fluid overload as large volumes of saline are given. Serial calcium, creatinine and electrolyte results are trended, and cardiac monitoring is used because both high calcium and the rapid shifts during treatment affect conduction. Neurological checks track confusion, and safety measures protect a drowsy patient from falls. Bowel management addresses constipation. Finally, the nurse supports conversations about goals of care, because this complication often marks a turning point in the course of cancer.
Conclusion
In this case, a lung cancer produced a hormone that imitates parathyroid hormone but ignores the body's feedback, releasing calcium from bone and retaining it in the kidney. High calcium then caused the kidneys to lose water, and dehydration reduced kidney function, creating a cycle that drove calcium even higher. The same mechanism explains her confusion, constipation, polyuria, low phosphate and ECG changes, and it explains why fluids, calcitonin and bone-targeted drugs each have a role in treatment.
References
Guise, T. A., & Wysolmerski, J. J. (2022). Cancer-associated hypercalcemia. New England Journal of Medicine, 386(15), 1443-1451. https://doi.org/10.1056/NEJMcp2113128
Rogers, J. L. (Ed.). (2023). McCance & Huether's pathophysiology: The biologic basis for disease in adults and children (9th ed.). Elsevier.
Stewart, A. F. (2005). Hypercalcemia associated with cancer. New England Journal of Medicine, 352(4), 373-379. https://doi.org/10.1056/NEJMcp042806
How this NUR 315 Module 6 example is structured
The paper begins with the case and the laboratory pattern, high calcium with suppressed parathyroid hormone, that points to the cause. Normal calcium regulation comes next, because the disease is a hijacking of that system. The mechanism section explains how the tumor's hormone mimics parathyroid hormone at bone and kidney, and then describes the cycle in which high calcium causes water loss, water loss reduces kidney function, and reduced function keeps calcium high. A table links each symptom and value to its mechanism. The treatment section explains how each therapy breaks the cycle at a particular point, and a nursing section follows.
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Send the NUR 315 Module 6 assignment instructions and rubric, along with the case or electrolyte disorder assigned. The desk writes the case study to that prompt in 24 to 48 hours, and the first is free. The paper above is an original model document written by our desk, not a submitted student paper and not an official Southern New Hampshire University document.
NUR 315 Module 6 questions, answered
What does NUR 315 Module 6 usually focus on?
Later modules in pathophysiology courses commonly cover the renal system and fluid and electrolyte balance, where laboratory values begin to explain themselves. An assignment in this part of NUR 315 may ask students to analyze a case of kidney disease or an electrolyte disorder and trace its signs and symptoms to the underlying mechanism.
Why does hypercalcemia cause so much fluid loss?
High calcium interferes with the kidney's ability to concentrate urine, so the patient passes large volumes of dilute urine and becomes dehydrated. Dehydration lowers kidney blood flow, which reduces calcium excretion and raises calcium further. Explaining that loop is central to any analysis of severe hypercalcemia.
Should a pathophysiology case study discuss treatment?
Many prompts ask for it, and treatment is easiest to explain when it is tied to the mechanism. Rather than listing drugs, state which step in the process each therapy interrupts. That approach shows understanding of both the disease and the rationale for care.