However in certain situations such as intolerable pain due
However, in certain situations such as intolerable pain due to involvement of local tissue, repeated skin ulceration, or fistula formation, surgical excision is unavoidable. Here we present a case of huge lumbosacral area TC secondary to ESRD that required surgical excision and immediate flap reconstruction for defect management.
Case report A 65-year-old female patient presented at the outpatient department (OPD) with a 1-year history of a progressive, enlarging mass over her right buttock area. The mass was firm, freely moveable, severe-tender, with irregular borders, and had protruded out of the skin (Fig. 1). The patient medical history included significant underlying conditions such as ESRD under regular hemodialysis for 10 years and congestive heart failure. The mass was initially noted approximately 2 years previously by the patient as a small, painful nodule with slight progression in size. She sought initial medical attention 1 year previously at the general surgery OPD. An abscess was initially suspected, and a small amount of whitish discharge was found after incision and drainage under local anesthesia. Follow-up computed tomography (Fig. 2) showed a solid calcified mass over the subcutaneous area of the right buttock, 34 mm in diameter, which was not connected with the underlying muscle or bone. Although total excision under general anesthesia was suggested, the operation was cancelled due to unfavorable heart ejection fraction of this patient. However, the nodule gradually enlarged and became a firm tumor, so the patient was transferred to the Plastic and Reconstructive Surgery OPD. Repeat episodes of skin erosion in the overlying region was noticed during OPD follow up, and finally skin breakage occurred with a visible 5 cm × 8 cm, multilobular yellowish mass protruding through the skin. She complained of local pain and, due to the severe interference to her daily activities, excision of the tumor with local flap reconstruction was arranged. Reviewing her family history, there was no similar condition within the family. No unknown fever or weakness had occurred during this period of time, and there were no generalized, systemic complaints. The auda results of blood sampling (Table 1) revealed hypercalcemia in previous examinations (calcium = 10.7 mg/dl 2 years previously, 11.4 mg/dl 1 year previously; reference range, 9–10.5 mg/dl) and normocalcemia (calcium = 9.9 mg/dl) just prior to the operation. In addition, hyperphosphatemia (phosphorous = 6.97 mg/dl; reference range, 2.4–4.1 mg/dl) and hyperparathyroidism (intact parathyroid hormone = 2270 pg/ml; reference range, 10–55 pg/ml) was found. Uric acid was also checked and was within normal limits (6.7 mg/dL). An operation was performed for total excision of the tumor, which extended 5 cm into the skin. The resulting huge soft tissue defect and sacral bone exposure was too large for primary closure (Fig. 3). Hence, a right gluteus maximus myocutaneous flap was rotated to obliterate the dead space and reconstruct the soft tissue defect. Grossly, an ill-defined and firm subcutaneous tumor with yellow–white calcareous material was noted, weight 143 g and 7.8 cm × 6.8 cm × 6 cm in size (Fig. 4). Pathology demonstrated amorphous calcified material surrounded by granulomatous reaction and fibrous tissue (Fig. 5). A TC was diagnosed. After the operation, continuous low phosphate diet and oral medication with phosphate binding antacid was prescribed (aluminum/magnesium hydroxide three times a day during a meal) and no local recurrence was noted at the 1-year follow-up (Fig. 6). The patient was capable of sitting and lying down without any discomfort and had good functional recovery.
Discussion TC is a rare, benign lesion that was first named by Inclan et al in 1943. TC is characterized by tumor-like deposits of calcium, which are usually in periarticular regions. The joints are usually spared, and lesions may be multiple. The tumor itself is usually painless, although mass effects ranging from local pain caused by neural involvement to functional impairments may also be present. TC can be classified into three clinical types based on pathogenesis: (1) primary normophosphatemic TC (sporadic); (2) primary hyperphosphatemic TC (familial); and (3) secondary TC. The first type affects young patients (without any familial history) and is usually a single lesion with low chance of recurrence after excision. The second type is hereditary and is a metabolic disease with decreased fractional phosphate excretion and increased 1,25-dihydroxyl-vitamin D synthesis. It affects multiple sites including teeth, vessels, diaphysis, and cranium, and recurrence is common. The third type derives from systemic diseases that promote ectopic calcification such as hyperparathyroidism and sarcoidosis. Secondary hyperparathyroidism due to poor blood phosphate level control in an ESRD patient, just like this patient, is the primary cause in third type patients.