Malignant Peripheral Nerve Sheath Tumor of the Adrenal Gland: A De novo Case.

Sir,

Malignant peripheral nerve sheath tumors (MPNSTs), which arise from peripheral nerve branches or sheaths of peripheral nerve fibers,[1] are rarely present in adrenal glands.[23456789] Most of these tumors occur in association with neurofibromatosis, ganglioneuroma, or pheochromocytoma.[8] We report extremely rare case of a MPNST of adrenal gland not associated with neurofibromatosis, ganglioneuroma, or pheochromocytoma.

A 40-year-old female with Type 2 diabetes mellitus (on metformin 500 mg and teneligliptin 20 mg) and hypertension (on telmisartan 40 mg) for 3 years was referred to our endocrine center for the evaluation of left adrenal mass, which was detected incidentally on ultrasonography abdomen, done for vague abdominal pain of one week duration. The general physical and systemic examination was unremarkable. Contrast-enhanced computed tomographic scan of the abdomen showed left adrenal mass, 6 cm in maximum dimension with necrosis. Precontrast Hounsfield units (HU) 40, portal venous phase HU140, delayed phase HU 90, absolute washout 50% and delayed washout 35.7% [Figure 1]. Overnight 1 mg dexamethasone suppression test (0.4 mg/dL), 24 urinary metanephrines 100 mg (74–297 mg/24 hours), normetanephrines 120 mg (73–800 mg/24 hours) and serum dehydroepiandrosterone sulfate 1.2 ng/mL (0.36–7.82 ng/mL) were normal. She was subjected to open left adrenalectomy.

Figure 1

Contrast enhanced CT scan of the abdomen showing left adrenal mass with necrosis (arrow)

On gross examination, the tumor measured 10 × 5 × 6 cm, replaced the entire adrenal gland, was encapsulated and cut surface was yellowish-white with small areas of hemorrhages. Microscopy revealed a spindle cell neoplasm arranged in a whorling pattern [Figure 2], high cellularity, numerous mitotic figures, and zones of tumor necrosis [Figure 3] with positive immunoreactivity for S100 protein and vimentin. The tumor cells were negative for cytokeratin (CK), smooth muscle antigen (SMA), desmin, epithelial membrane antigen (EMA), and Melan A. The patient is on follow up and is doing well 3 years after the surgery. A recent PET-CT has shown no evidence of recurrent or metastatic disease.

Figure 2

Microphotograph revealing MPNST with spindle cells in a whorling arrangement (arrow) (H and E ×400)

Figure 3

Microphotograph revealing zones of tumor necrosis (arrow) (H and E ×400)

MPNST is a rare soft tissue sarcoma of ectomesenchymal origin. To the best of our knowledge, only 8 cases of MPNST of the adrenal gland has been reported in the literature [Table 1] and 7 of these occur in association with neurocutaneous syndromes.[23456789] Our case is only the second report of adrenal MPNST without any history of neurofibromatosis or combined tumor. These tumors often have histopathological similarities with other spindle cell sarcomas such as leiomyosarcoma and fibrosarcoma. In 50 to 90% of MPNSTs, the cells are immunoreactive to S-100 protein staining.[10] Patients with MPNSTs have a poor prognosis and metastasize to the lung, liver, brain, soft tissue, bone, regional lymph nodes, skin, or retroperitoneum. Adverse prognostic factors for MPNST include tumor size ≥10 cm, partial resection, nuclear p53 expression and lack of S-100 immunoreactivity.[11]

Table 1

Summary of reported cases of adrenal MPNST

Author	Age/sex	Tumor site	Composite tumor or related disease	Treatment
Chandrasoma et al.[2]	30/M	Left	Ganglioneuroma	Adrenalectomy
Min et al.[3]	39/F	Left	Pheochromocytoma	Adrenalectomy
Miettinen et al.[4]	38/F	Left	Pheochromocytoma	Adrenalectomy
Sakaguchi et al.[5]	48/M	Bilateral	Neurofibromatosis Pheochromocytoma	Radiation Chemotherapy
Ch’ng et al.[6]	37/F	Left	Pheochromocytoma	Adrenalectomy and Nephrectomy
Namekawa et al.[7]	42/F	Left	Pheochromocytoma	Adrenalectomy and Nephrectomy
Park et al.[8]	31/F	Left followed by right	De novo	Adrenalectomy
Baisakh et al.[9]	24/M	Left	Neurofibromatosis	Adrenalectomy
Present case	40/F	Left	De novo	Adrenalectomy

MPNST: malignant peripheral nerve sheath tumor

CONCLUSION

MPNST of the adrenal gland is extremely rare and this is only the second report about MPNST of the adrenal gland without any history of neurofibromatosis or combined tumor.

Consent

Informed and written consent was obtained from the patient for participation the study and data publication.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.