Congenital hamartoma of the scalp with meningothelial, sebaceus, muscular, and immature glandular components

Meningothelial Hamartoma of the Scalp: Clinicopathologic Review of an Unusual Tumor Mimicking a Vascular Neoplasm With Review of Literature

ABSTRACT

An unusual benign skin lesion is reported in a 19-year-old man with no significant medical history. The lesion had been present since he was an infant and had been slowly enlarging over the past 15 years. The lesion caused pain and discomfort, and the patient underwent an excisional biopsy. Histologic examination showed a subcutaneous lesion with ill-defined borders and peripheral areas of infiltration between adnexal structures. The lesion was composed of small round to ovoid cells embedded in a collagenous stroma with prominent cystic pseudovascular appearing channels causing a pseudopapillary or lymphangitic appearance that mimicked a vascular neoplasm. Immunohistochemistry performed showed positive staining for EMA, progesterone receptor, D2-40, and vimentin within the lesional cells. The tumor cells were negative for cytokeratin AE1/AE3, CD34, CD31, HHV-8, STAT6, SMA, Desmin, S-100, Melan A, and HMB45. A next-generation sequencing study using a hybrid capture-based panel examining 50 commonly mutated genes in human neoplasia was performed and showed no molecular alterations suggesting a nonneoplastic nature. Based on the clinical presentation, histologic features, and results of ancillary studies, the case was diagnosed as a hamartoma of the scalp with meningothelial-like elements. Reported cases of this lesion have behaved in a benign manner; however, as the histologic differential includes low-grade malignant vascular neoplasms such as angiosarcoma, it is important to recognize the salient features of this lesion.

Bilateral Nipple Enlargement as a Secondary Effect of Anabolic Drugs: A Histopathological Mimicker of Smooth Muscle Hamartoma

Smooth muscle hamartoma are usually solitary and congenital, may affect the genital area and nipples. Histopathologically, they are characterized by the presence of mature smooth muscle bundles. We present a 40 year-old male with bilateral nipple enlargement excised with clinical suspicion of bilateral leiomyoma. Skin biopsy shows mature, irregularly arranged smooth muscle bundles and lactiferous ducts between them. Immunohistochemistry is positive for smooth muscle actin, desmin and fumarase, but negative for estrogen and progestogen receptors. The presence of lactiferous ducts excludes bilateral leiomyomas. Even when, histopathologically, this can be interpreted as the nipple-type of muscular hamartoma of the breast, clinical history favors an anabolic drug-induced lesion. Bodybuilders present gynecomastia and nipple enlargement as frequent problems, but we have not found any histopathological description of these nipple lesions. We consider that dermatologists should be aware of the presence of them and dermatopathologists should know their histopathological features to avoid misdiagnosis as neoplasms.

Rudimentary Meningocele of the Scalp: A Pitfall in the Diagnosis of Vascular Neoplasms

We present a case of sequestrated meningocele in a 1-year-old girl, who presented with a 1x1cm occipital swelling since birth. CT brain revealed the soft tissue swelling to be extracranial. She underwent surgical excision of the specimen and the excised mass was sent for histopathological examination. The specimen consisted of skin and subcutaneous tissue measuring 2 x 1 x 1 cm. The entire tissue was paraffin processed. Multiple sections studied from the lesion showed an ill circumscribed locally infiltrative dermal lesion. The lesion was composed of whorled proliferations of meningothelial cells enclosing pseudovascular spaces. Immunohistochemically the lesion was positive for EMA, Desmin, and negative for endothelial markers. The present case was documented as a rare case of a rudimentary meningocele.

Rare congenital meningothelial hamartoma of the scalp with progressive growth

Scalp lesions are common pediatric findings that present for neurosurgical evaluation and management. The majority will be benign. Meningothelial hamartomas represent a rare subset of congenital cutaneous lesions with the potential for intracranial extension and microscopic infiltration of the surrounding tissues. The authors report in this paper a case of meningothelial hamartoma of the scalp that demonstrated serial growth and invasion of the scalp. The degree of microscopic involvement and growth necessitated close follow-up and repeat excision.

The scalp hair collar and tuft signs: A retrospective multicenter study of 78 patients with a systematic review of the literature

BACKGROUND

Hair collar sign (HCS) and hair tuft of the scalp (HTS) are cutaneous signs of an underlying neuroectodermal defect, but most available data are based on case reports.

OBJECTIVE

We sought to define the clinical spectrum of HCS and HTS, clarify the risk for underlying neurovascular anomalies, and provide imaging recommendations.

METHODS

A 10-year multicenter retrospective and prospective analysis of clinical, radiologic, and histopathologic features of HCS and HTS in pediatric patients was performed.

RESULTS

Of the 78 patients included in the study, 56 underwent cranial and brain imaging. Twenty-three of the 56 patients (41%) had abnormal findings, including the following: (1) cranial/bone defect (30.4%), with direct communication with the central nervous system in 28.6%; (2) venous malformations (25%); or (3) central nervous system abnormalities (12.5%). Meningeal heterotopia in 34.6% (9/26) was the most common neuroectodermal association. Sinus pericranii, paraganglioma, and combined nevus were also identified.

LIMITATIONS

The partial retrospective design and predominant recruitment from the dermatology department are limitations of this study.

CONCLUSIONS

Infants with HCS or HTS are at high risk for underlying neurovascular anomalies. Magnetic resonance imaging scans should be performed in order to refer the infant to the appropriate specialist for management.

Meningothelial hamartoma associated with nevus sebaceus

Meningothelial hamartoma is a rare lesion of ectopic meningothelial elements that usually presents on the scalp at birth or in early childhood. The characteristic spindle cells infiltrate through collagen and stain positively for epithelial membrane antigen and vimentin but are negative for CD31 and CD34. This distinguishes meningothelial hamartoma from vascular tumors. Nevus sebaceus is a fairly common lesion that has been associated with several different benign tumors, including trichoblastoma and syringocystadenoma papilliferum. We describe the case of a 17-month-old girl who presented with a meningothelial hamartoma in association with a nevus sebaceus. To the best of our knowledge, this is the second case reported.

Neurogenic tumors of soft tissue

Neurogenic tumors are an uncommon yet important category of soft tissue tumors in children and adolescents because of their frequent association with various genetic syndromes. The heterogeneous cellular composition of the peripheral nerve and the wide metaplastic capacity of the neural crest and its derivatives generate a variety of neoplasms with neurogenic differentiation. This article reviews the clinicopathologic features and differential diagnosis of neurogenic tumors in the first two decades of life, and highlights use of selected ancillary methods for diagnosis.

Case report: Meningothelial hamartoma of the scalp in a 9-year-old child

Meningothelial hamartomas represent a collection of meningothelial elements in an ectopic location. Lesions are histologically characterized as a proliferation of connective tissue elements and small- and medium-sized vessels admixed with meningothelial elements. Lesions are most often located on the scalp, present at birth, and do not extend past the subcutis. We discuss the case of a 9-year-old African American girl presenting with one such lesion on the parietal aspect of the scalp.

Multiple tiny ectopic sebaceous glands discovered throughout entire esophageal tract

A 45-year-old woman complaining of abdominal fullness was referred for endoscopic examination. She was a non-smoker and non-drinker. An endoscopic examination revealed the presence of more than 100 tiny, rounded, elevated, yellowish lesions <0.5 mm in diameter scattered throughout the upper and lower esophagus. Based on the endoscopic examination results, her stomach manifested symptoms of mildly superficial gastritis. Histopathologic examination of the esophagus biopsy specimen revealed that some of the lobules of the cells displayed typical sebaceous differentiation covered by a squamous epithelium. No evidence of inflammatory reaction, hair follicles, or malignancy was found. The patient's blood and serum findings were unremarkable. Our final diagnosis was multiple tiny ectopic sebaceous glands in the esophagus. This is an interesting and rare case of esophageal sebaceous glands distributed throughout the entire esophagus. Because there were no esophageal symptoms or/and eating problems, the patient did not require endoscopic surgery or other treatment. Follow-up examinations were recommended at intervals between 6 months and 1 year. At the 2-year follow-up, an endoscopic examination revealed no change in the size or the number of the tiny ectopic esophageal sebaceous glands.

Selective pathologies of the head and neck in children: a developmental perspective

The range of pathology seen in the head and neck region is truly amazing and to a large extent probably mirrors the complex signaling pathways and careful orchestration of events that occurs between the primordial germ layers during the development of this region. As is true in general for the entire discipline of pediatric pathology, the head and neck pathology within this age group is as diverse and different as its adult counterpart. Cases that come across the pediatric head and neck surgical pathology bench are more heavily weighted toward developmental and congenital lesions such as branchial cleft anomalies, thyroglossal duct cysts, ectopias, heterotopias, choristomas, and primitive tumors. Many congenital "benign" lesions can cause significant morbidity and even mortality if they compress the airway or other vital structures. Exciting investigations into the molecular embryology of craniofacial development have begun to shed light on the pathogenesis of craniofacial developmental lesions and syndromes. Much more investigation is needed, however, to intertwine aberrations in the molecular ontogeny and development of the head and neck regions to the represented pathology. This review will integrate traditional morphologic embryology with some of the recent advances in the molecular pathways of head and neck development followed by a discussion of a variety of developmental lesions finishing with tumors presumed to be derived from pluripotent/progenitor cells and tumors that show anomalous or aborted development.