|Year : 2021 | Volume
| Issue : 1 | Page : 60-62
Congenital Cutaneous Peripheral Primitive Neuroectodermal Tumor (pPNET) of Scalp: Youngest Case So Far
Parveen Kumar1, Shasanka Shekhar Panda1, Sarika Singh2, Yogesh Kumar Sarin1
1 Department of Pediatric Surgery, Maulana Azad Medical College, New Delhi, India
2 Department of Pathology, Maulana Azad Medical College, New Delhi, India
|Date of Submission||21-Mar-2020|
|Date of Decision||26-Apr-2020|
|Date of Acceptance||03-May-2020|
|Date of Web Publication||11-Jan-2021|
Dr. Shasanka Shekhar Panda
Department of Paediatric Surgery, Maulana Azad Medical College, New Delhi - 110 002
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Congenital cutaneous peripheral primitive neuroectodermal tumor (pPNET) is very rare and also very rarely located in scalp. Only two cases of PNET as primary tumor in scalp are reported so far in the literature. Non mutilating surgical excision, combined with chemotherapy and radiotherapy are used in treating these rare tumors. We present the youngest case report of PNET of scalp in 10-month-old girl who was managed by surgical excision with good cosmetic outcome and disease-free 20 months post-operative period.
Keywords: Ewing's sarcoma, peripheral neuroectodermal tumor, peripheral primitive neuroectodermal tumor, scalp
|How to cite this article:|
Kumar P, Panda SS, Singh S, Sarin YK. Congenital Cutaneous Peripheral Primitive Neuroectodermal Tumor (pPNET) of Scalp: Youngest Case So Far. J Indian Assoc Pediatr Surg 2021;26:60-2
|How to cite this URL:|
Kumar P, Panda SS, Singh S, Sarin YK. Congenital Cutaneous Peripheral Primitive Neuroectodermal Tumor (pPNET) of Scalp: Youngest Case So Far. J Indian Assoc Pediatr Surg [serial online] 2021 [cited 2022 Oct 6];26:60-2. Available from: https://www.jiaps.com/text.asp?2021/26/1/60/306708
| Introduction|| |
Peripheral primitive neuroectodermal tumor (pPNET) is very rare. The congenital nature and scalp location makes the index case rarer. Extensive search revealed only two cases of PNET as primary tumor in the scalp before this case., Our case is the youngest so far and had larger size in comparison to other two cases.
| Case Report|| |
A 10-month-old girl was admitted with a large painless swelling of the scalp present since birth, which was progressively increasing in size. There were no other systemic complaints. Examination revealed a very pale infant with a 15 cm × 15 cm nonilluminant cystic swelling over the parieto-occipital region of the scalp, more so on the left side [Figure 1].
Hemoglobin at admission was 4 g% that necessitated blood transfusion. Rest of the blood investigations including alpha-fetoprotein was normal. Computerized tomography (CT) revealed a large 14 cm × 13 cm size well-defined thin-walled cystic lesion in the left parieto-occipital region having few internal septations; there was no intracranial communication.
Clinical differential diagnosis of lymphangioma and cystic teratoma was kept in mind. Excision of the cyst in toto was done; about 10% of the tumor had solid consistency [Figure 2]. The biopsy was reported as PNET/extraskeletal Ewing's sarcoma (EES); tumor cells were positive for CD99 (focally), neuron-specific enolase (NSE), and vimentin [Figure 3].
|Figure 3: Distinctive cytoplasmic membrane staining pattern with CD99 (×600)|
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Metastatic workup including skeletal survey, thoracic and abdominal CT scan, and bone scan was negative. As these tumors are known to be high-grade lesions histologically, it was planned to administer adjuvant chemotherapy as per the guidelines of the European Pediatric Soft Tissue Sarcoma Study Group, but parents refused any further treatment.
She is under close surveillance and disease-free 20 months postoperatively presently.
| Discussion|| |
Primitive neuroectodermal tumor/Ewing's sarcoma (PNET/ES) is a single clinical, morphological, and molecular small round cell tumor entity. This family of tumors includes classical ES of bone, EES, and Askin tumors of the chest wall and primitive neuroectodermal tumors of the bone or soft tissues. They all share a common neural histiogenesis and tumor genetics, so considered together. These are generally found in deep soft tissue or bone of young male patients, with poor behavior.
Extraskeletal PNET was first described in 1975 by Angervall and Enzinger. It is known for its aggressive nature, local recurrence, and distant metastasis. Metastasis is usually to lungs and bone, lymph nodes being rarer. Scalp PNET has been published in literature in only two cases so far, that too in 15 and 11 years old., Furthermore, they had smaller size in comparison to our case.
Dermal PNET/ES is exceedingly rare. When present in soft tissue, PNET/ES are usually deeply seated in subcutis or muscle, but rarely occur as a primary tumor in the skin. These have been mainly reported as single cases or small series from 1 to 2 decades ago, with little molecular data. In the dermis, PNET/ES are not anticipated and can be confused morphologically with several other round dermal-specific cell tumors. In this situation, it needs to be distinguished from other small round cell tumors of soft tissue, which may be occasionally present in the skin (such as rhabdomyosarcoma and neuroblastoma), from lymphoblastic lymphoma presenting in skin, and from basaloid or small round cell tumors commonly seen in the skin (such as carcinomas of appendageal origin and Merkel cell carcinoma).
In a series by Ehrig et al., dermal or cutaneous PNET/ES is more common in women (average age is 16 years) than in men, unlike deep intramuscular or intraosseous PNET/ES (tends to be more common in young men). The behavior for cutaneous PNET/ES is generally favorable, unlike its deep counterpart. The factors attributable to relatively good behavior of dermal PNET/ES are small size and superficial location, leading to early detection.
Diagnosis on histology can be made by the presence of dermal and occasionally superficial subcutaneous sheeted round blue cell tumor with vague pseudo-rosetting, globular cytoplasmic periodic acid-Schiff reactivity, a distinctive staining pattern with CD99 (MIC2 gene product), and negativity for the immunoprofile of other small round cell tumors. Our case, on histopathological examination, had round cells with vesicular nuclei, speckled chromatin, and eosinophilic cytoplasm, with occasional mitosis and apoptosis. Immunohistochemistry showed CD99 positivity (focally), NSE, and vimentin positive suggestive of PNET/ES. Translocation t(11, 22) leading to chimeric transcripts is a feature of PNET/ES, but its identification may be difficult on small sample size. This study could not be done due to nonavailability of resources at our center.
Therefore, correct diagnosis and proper treatment including adjuvant therapy are required for this superficial tumor. One might argue whether adjuvant therapy is even indicated, but these are high-grade lesions histologically and have been and should be treated accordingly. The better prognosis for these tumors is based on superficial location and small size. However, our patient has survived free of disease for 20 months without any adjuvant therapy.
PNET/ES family tumors are radiosensitive, but may not be offered as primary modality. The 12 patients treated solely with radiotherapy plus chemotherapy had 5-year EFS of 16% and local disease progression was observed in 58% of them, in a study of 57 adult patients at a single center. The favorable outcome of radiotherapy as primary modality may be attributed to favorable sites (extremities) and small tumor size. Others recommend surgical resection as appropriate option for local control in PNET/ES. The current recommendations for postoperative radiotherapy include positive or close margins, gross residual disease, or a poor histological response to induction chemotherapy.
| Conclusion|| |
We present the youngest case report of PNET/ES of scalp in a 10-month-old girl. Nonmutilating surgical excision, combined with chemotherapy and radiotherapy (when indicated) are forerunner of success in treating these rare tumors.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]