The hybrid epidermoid and apocrine cyst. A combination of apocrine hidrocystoma and epidermal inclusion cyst

A New Case of Hybrid Epidermoid and Apocrine Cyst

We described a new case of a hybrid epidermoid and apocrine cyst, known to be a rare histopathological entity. The cyst was located in the axillary region and completely excised, without complication. The diagnosis was made at the histological analysis, where we found a cystic lesion in the dermis, lined with both epidermoid and apocrine epithelium.

Trichilemmal Cysts With Divergent Ductal Differentiation: A Series of 4 Cases

ABSTRACT

Trichilemmal cysts are common clonal tumors with a predilection for the scalp. They are composed of an outer epithelial wall resembling the outer root sheath in the isthmus of the hair follicle and a central core of compact keratin. Sweat duct differentiation is exceptional with only one convincing case reported to date. Here, we sought to characterize the clinicopathological characteristics of sweat duct differentiation in trichilemmal cysts. We reviewed all cases of trichilemmal cyst diagnosed at our institution between 2008 and 2019. Ductal structures were found in 4 of 411 cases (0.97%). Subjects included 2 male and 2 female patients with a median age of 37.5 years (range 34-55). The ducts were lined by attenuated epithelial cells and immunoreactive for polyclonal carcinoembryonic antigen and cytokeratin 7. Ductal differentiation involved a median of 7.5% (range 1%-50%) of the cyst wall. All 4 cases were from the scalp and treated with local excision. No recurrence was identified with a median follow-up period of 1.5 years (range 1-12 years). In summary, sweat duct differentiation in trichilemmal cysts is rare but likely under recognized. Conceptually, we suggest it represents a type of divergent cellular differentiation within a clonal neoplasm rather than a retention cyst or hybrid cyst.

A Rare Case of a Pilar Cyst With Ductal Differentiation

Pilar cysts are common squamous-lined cysts that typically occur on the scalp. They are believed to arise from the isthmus of anagen hairs or from the sac surrounding catagen and telogen hairs. The authors describe a rare case of a pilar cyst with prominent ductal differentiation, presumably of eccrine derivation. Sweat duct differentiation has been described in a myriad of cutaneous neoplasms and rarely within epidermoid cysts. The authors could only find one other case in the literature describing a pilar cyst with sebaceous and apocrine differentiation. The clinicopathologic findings are described here.

Epidermal inclusion cyst of the breast: A literature review

An epidermal inclusion cyst (EIC) of the breast is a rare, benign condition that may potentially be malignant. The present study conducted a systematic review of the literature in order to identify pathological hypotheses, clinical characteristics, and diagnostic and treatment options. A search for relevant studies was conducted through the Scopus, Embase and Medline databases during September 2014. The search term employed was ῾epidermal inclusion cyst breast᾽. Studies were selected if they contained adequate information regarding symptoms at presentation, diagnostic tools, pathology, characteristics, type of procedure performed and follow-up routines. A total of 35 papers describing 91 patients affected by EIC of the breast were identified. Following this, a total of 82 patients, including an additional case supplied from the present study, were selected for further analysis. EIC of the breast typically occurs during the fifth decade of life. A palpable mass of the breast was present in 65 (79%) patients. Ultrasonographic imaging was consistently utilized as a diagnostic tool in all the cases analyzed, whereas fine-needle aspiration cytology was used in 70% of the cases and mammography in 65%. No tumor recurrence was reported at a mean follow-up time of 53 months. The present study demonstrated that elliptical excision is the preferred treatment for EIC of the breast, with pathological analysis required to exclude malignancy.

Apocrine hidrocystoma of the lower lip: a case report and literature review

The hidrocystomas (HCs) are cystic forms of sweat gland resulting from proliferation of the apocrine secretory coil or eccrine duct. Apocrine -HCs are cystic lesions that arise from the apocrine secretory coil, while eccrine -HCs represent retention cysts of the eccrine duct. The commonest site for such lesions is around the eye, and they may also occur on the ears, scalp, chest, shoulders, or feet. However, HCs of the perioral region are uncommon. The differential diagnosis with minor salivary gland cyst or cystic neoplasms often poses a problem in this site. Here we report a rare case of apocrine -HC of the right lower lip for which excisional biopsy of the lesion was performed. Histopathologically, the lesion was a unilocular cyst lined by a double-layered epithelium of the apocrine secretory type. Immunohistochemically, the secretory epithelium was positive for mammaglobin, gross cystic disease fluid protein 15 (GCDFP-15), cytokeratin 7 (CK 7) and CK18, and the myoepithelium was positive for alpha-smooth muscle actin (α-SMA) and weakly positive for S100 protein. Here we present this very rare case of apocrine -HC of the lower lip, and discussed regarding differential diagnosis with minor salivary gland cystic lesion in the lip.

Hybrid cysts: a clinicopathological study of seven cases

Hybrid cysts develop from more than two components of the pilosebaceous unit. The pathogenesis of this unusual disease has not yet been elucidated. The aim of this study was to assess the clinical and histopathological features of hybrid cysts. Histological sections of seven cases indexed as hybrid cysts were reviewed from 1996-2009 at the Department of Dermatology, Eulji Medical Center, Seoul, Korea. Hospital charts and slides were retrospectively evaluated. All cases had a combination of an epidermal cyst and a pilomatricoma with sharp transitional zones. The epidermal cyst lining was composed of thickened stratified squamous epithelium with a granular layer. Basophilic cells, shadow cells and the contents of the pilomatricoma were present in all lesions. There were no differences in the clinical features between patients with hybrid cysts and others with single cystic lesions. There were five women and two men, ranging in age from 11 to 50 years (mean 27 years). The most common sites were the upper extremities. None of the patients had any sign of Gardner's syndrome. Hybrid cysts are an interesting pathological phenomenon. Further study is needed to analyze hybrid cysts to improve our understanding of their pathogenesis and development from tumours of the pilosebaceous unit.

Umbilical epithelial cyst in secondary abdominoplasty: case report

BACKGROUND

A retained epidermal inclusion cyst (REIC) at the umbilicus after abdominoplasty is a rare phenomenon that has had limited description in the literature. This case report describes a woman who came for a secondary abdominoplasty and presented intraoperatively with an unexpected large epidermal inclusion cyst.

CASE REPORT

The woman was disappointed with the result of a previous abdominal surgery. She initially had severe postoperative wound infection followed by revision surgery and subsequent intermittent secretion in the umbilical region. Then seven years later, hip backplasty combined with liposuction was performed. After another six months, full abdominoplasty combined with exploration of the umbilical region was performed. The surgical exploration showed a large, 3×4.5 cm indurated structure highly suspected to be a REIC. The excision was effective without recurrence, and the healing was uneventful. The patient was very satisfied with the result.

DISCUSSION

As a typical epidermoid cyst, REIC consists of squamosed stratified epithelial cells that continue to the granular layer. In most cases, the cyst is filled with a keratin-like material. When this tumor is solid, a histologic evaluation may be necessary. When the cyst has been excised, the umbilicus gets reconstructed after the abdominoplasty. A history of poor healing in the umbilicus area may arouse suspicion of an epidermoid cyst. Epidermoid cysts in the region of the umbilicus could easily be overlooked in preparation of the umbilicus.

Two Pilosebaceous Cysts with Apocrine Hidrocystoma in One Biopsy Site: A Spectrum of the Same Disease Process?

A 28-year-old woman presented with multiple, asymptomatic, erythematous to bluish papules located on the chest. Histopathologically, three round, well defined cystic structures were seen on the upper and lower dermis. The first cyst was milia, the second was apocrine hidrocystoma and the other, largest cyst was an eruptive vellus hair cyst (EVHC). A diagnosis of multiple pilosebaceous cysts combined with apocrine hidrocystoma was made. Since the milia and EVHC originate from the pilosebaceous unit, and the apocrine duct opens to the pilosebaceous orifice, we suggest that they can occur simultaneously in the same unit.

Epidermal inclusion cyst of the umbilicus following abdominoplasty

The incidence of retained epidermal inclusion cyst at the site of the umbilicus following abdominoplasty has yet to be well documented. Compliant patients who are seen in scheduled follow-up, and who display signs of infection or wound issues at the site of the umbilicus, usually have these factors addressed before inclusion cysts manifest. Here, however, we present a patient who underwent abdominoplasty, lost her surgeon because of geographic relocation, presented to our office 1 year following surgery with a large retained umbilical epidermal inclusion cyst. This case gave us a unique opportunity to observe a well-developed retained umbilical epidermal inclusion cyst. Her evaluation and management are reviewed in an effort to familiarize the practicing plastic surgeon with a rare, but significant potential complication of abdominoplasty.

Epithelial Remnants of Isthmus-Catagen Cysts

The histopathologic diagnosis of isthmus-catagen cysts is typically rendered with ease at scanning magnification. Episodically, diagnostic problems may arise when the outermost epithelial portion of the cyst wall separates from the remainder of the cyst. If a histopathologist is unaware of this phenomenon, the findings may be misinterpreted.

Hybrid cyst: case reports and review of 15 cases in Japan

Hybrid cyst is a rare cystic lesion that includes more than two components of the pilosebaceous units. To clarify the clinical and pathological features of hybrid cysts, we report two cases and review 15 cases of hybrid cyst in Japan. On the whole, the age range was 12-73 years with a 2.95:1 female predominance and predilection for the scalp and face (46.7%). Most of the tumours presented as a solitary lesion and the size range was 2-45 mm. The most frequent histological type was the combination of infundibular and trichilemmal cysts (60.0%). Studying the clinicopathological features of hybrid cysts helps us in understanding the pathogenesis of diseases arising from pilosebaceous units.