Cutaneous Squamous Cell Carcinoma with Hypercalcemia of Malignancy and Skeletal Metastasis: Perioperative Case Report of Above-Knee Amputation

Summary

Here, we present a protocol to optimize perioperative management in patients with cutaneous squamous cell carcinoma complicated by malignancy-associated hypercalcemia.

Abstract

Malignancy-associated hypercalcemia (MAH) is one of the most frequent and life-threatening metabolic emergencies in oncology; however, it is rarely observed in cutaneous squamous cell carcinoma (cSCC). We report the perioperative management of a 48-year-old man with a left long-standing anterior knee scar complicated by recurrent ulceration. In August 2024, pathology confirmed well-differentiated cSCC; however, the patient was lost to follow-up. One year later, he presented with a progressive ulcer, fatigue, severe hypercalcemia, and renal impairment. Laboratory evaluation revealed suppressed parathyroid hormone (PTH) levels consistent with MAH. Computed tomography angiography showed extensive ulceration with bone destruction and vascular involvement, and FAPI-PET/CT confirmed local recurrence and skeletal metastases in the contralateral tibia.

Preoperative optimization consisted of isotonic crystalloid resuscitation, calcitonin, antiresorptive therapy with intravenous bisphosphonates or denosumab, and short-course continuous renal replacement therapy as indicated, allowing the patient to meet the physiologic criteria required for anesthesia induction. An above-knee amputation was performed using staged vascular control with continuous hemodynamic monitoring, followed by intensive care unit admission for targeted calcium-lowering therapy and organ support. The postoperative course was notable for the absence of fatal arrhythmias or deep surgical infection.

This case highlights that, in cSCC complicated by MAH, skeletal metastases, and chronic infection, adherence to explicit physiologic thresholds for anesthesia induction within a standardized perioperative pathway -- combined with advanced imaging for metabolic and anatomic stratification -- can create a safe operative window of time, mitigate acute risks, and improve the feasibility and safety of definitive oncologic surgery in a high-risk setting.

Introduction

Malignancy-associated hypercalcemia is one of the most common and life-threatening electrolyte emergencies among hospitalized patients with cancer^1,2. Evidence-based treatment centers on the use of isotonic crystalloid resuscitation, calcitonin, and antiresorptive therapy^1,2. In the perioperative setting, prevention of fatal arrhythmia and hemodynamic instability is paramount³. Pathophysiologically, humoral mechanisms mediated by parathyroid hormone-related peptide are most common; osteolytic hypercalcemia from skeletal metastas....

Protocol

This protocol was reviewed and approved by the Human Research Ethics Committee of the First Affiliated Hospital of Zhejiang University (IIT20240869A). All procedures performed in this study complied with institutional guidelines and adhered to the principles of the Declaration of Helsinki. Written informed consent was obtained from the patient for participation and publication of clinical data and images.

1. Initial assessment and stabilization

1. Upon admission, a baseline laboratory evaluation is performed, including total and ionized serum calcium, phosphate, magnesium, sodium, potassium, creatinine, liver funct....

Results

Following correction of metabolic derangements and achievement of all predefined physiologic criteria, the patient underwent a left above-knee amputation with successful staged vascular control and stable intraoperative hemodynamics. No episodes of fatal arrhythmia, circulatory collapse, or severe electrolyte disturbances occurred during the operation. Postoperatively, the patient was transferred directly to the intensive care unit, where ionized calcium, electrolytes, and arterial blood gases were closely monitored at 1.......

Discussion

FAPI-PET/CT visualizes cancer-associated fibroblast activity and, compared with fluorodeoxyglucose imaging, often provides higher tumor-to-background contrast across multiple sites; It can therefore be used for preoperative stratification at three levels: (i) anatomic extent, delineating skin, fascia, muscle, and bone involvement and proximity to neurovascular structures; (ii) disease burden, detecting occult skeletal and soft-tissue metastases and estimating lesion activity; and (iii) treatment strategy, informing feasi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.9% Normal Saline
14-Fr closed-suction drain	Ethicon	VAC14
18-G peripheral IV catheter	BD	381412
21-G butterfly needle	BD	367281
68Ga-FAPI Tracer	ITM Isotopen Technologien München AG	FAPI-46
Calcitonin (subcutaneous, 4 IU/kg)	Novartis	HUM/CT/4IU
Chlorhexidine-alcohol surgical scrub	3M	CHG-0150
Citrasate 4%	Fresenius	https://freseniusmedicalcare.com/en-us/products/disposables/concentrates/citrasate-liquid-acid/	Regional citrate anticoagulation solution
Denosumab 120 mg (subcutaneous)	Amgen	55513-710-01
Formalin (for biopsy fixation)	Sigma-Aldrich	HT501128
Furosemide injection (20 mg)	Sanofi	FRS20
IntelliVue MX450	Philips	https://www.philips.co.in/healthcare/product/HC866062/intellivue-mx450-patient-monitor	Standard 3-lead ECG monitor
Intravenous bisphosphonate	Roche	BNP-50
MEDRAD Stellant D	Bayer	https://radiology.bayer.com.au/products/medrad-stellant	Dual-syringe contrast injector (for CTA)
Myoplasty sutures (absorbable for fascia, non-absorbable skin)	Ethicon	VCP778H / MFS-29
Omnipaque 350	GE Healthcare	https://www.gehealthcare.com/products/contrast-media/omnipaque	CTA contrast: Iodinated contrast media (100 mL)
Perfusor Space	B. Braun	https://catalogs.bbraun.com/en-01/p/PRID00001226/perfusor-space	Patient-controlled analgesia pump
Prismaflex M100	Baxter	https://ecatalog.baxter.com/ecatalog/loadproduct.html?cid=20016&lid=10001&pid=822776	CRRT machine + calcium-free dialysate
Punch biopsy tool (6 mm)	Kai Medical	BP-60F
Surgical saw (oscillating)	Stryker	6208 System 6