Gardner's syndrome is a subtype of familial adenomatous polyposis (FAP). Gardner syndrome is an autosomal dominant form of polyposis characterized by the presence of multiple polyps in the colon together with tumors outside the colon. The extracolonic tumors may include osteomas of the skull, thyroid cancer, epidermoid cysts, fibromas, as well as the occurrence of desmoid tumors in approximately 15% of affected individuals.
Calcinosis cutis is an uncommon condition marked by calcium buildup in the skin and subcutaneous tissues. Calcinosis cutis can range in intensity from little nodules in one area of the body to huge, crippling lesions affecting a vast portion of the body. Five kinds of the condition are typically distinguished: calciphylaxis, idiopathic calcification, iatrogenic calcification, dystrophic calcification, and metastatic calcification.
An epidermoid cyst or epidermal inclusion cyst is a benign cyst usually found on the skin. The cyst develops out of ectodermal tissue. Histologically, it is made of a thin layer of squamous epithelium.
Birt–Hogg–Dubé syndrome (BHD), also Hornstein–Birt–Hogg–Dubé syndrome, Hornstein–Knickenberg syndrome, and fibrofolliculomas with trichodiscomas and acrochordons is a human, adult onset, autosomal dominant genetic disorder caused by a mutation in the folliculin (FLCN) gene. It can cause susceptibility to kidney cancer, renal and pulmonary cysts, and noncancerous tumors of the hair follicles, called fibrofolliculomas. The symptoms seen in each family are unique, and can include any combination of the three symptoms. Fibrofolliculomas are the most common manifestation, found on the face and upper trunk in over 80% of people with BHD over the age of 40. Pulmonary cysts are equally common (84%) and 24% of people with BHD eventually experience a collapsed lung. Kidney tumors, both cancerous and benign, occur in 14–34% of people with BHD; the associated kidney cancers are often rare hybrid tumors.
Hidradenoma refers to a benign adnexal tumor of the apical sweat gland. These are 1–3 cm translucent blue cystic nodules. It usually presents as a single, small skin-colored lesion, and may be considered closely related to or a variant of poromas. Hidradenomas are often sub-classified based on subtle histologic differences, for example:
Nevoid basal-cell carcinoma syndrome (NBCCS) is a rare inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine system, and bones. People with NBCCS are prone to developing various cancers, including a common and usually non-life-threatening form of non-melanoma skin cancer called basal-cell carcinomas (BCCs). Only about 10% of people with the condition do not develop BCCs; the vast majority of patients develop numerous BCCs.
Necrolytic migratory erythema is a red, blistering rash that spreads across the skin. It particularly affects the skin around the mouth and distal extremities; but may also be found on the lower abdomen, buttocks, perineum, and groin. It is strongly associated with glucagonoma, a glucagon-producing tumor of the pancreas, but is also seen in a number of other conditions including liver disease and intestinal malabsorption.
Urbach–Wiethe disease is a very rare recessive genetic disorder, with approximately 400 reported cases since its discovery. It was first officially reported in 1929 by Erich Urbach and Camillo Wiethe, although cases may be recognized dating back as early as 1908.
Cutaneous meningioma, also known as heterotopic meningeal tissue, and rudimentary meningocele is a developmental defect, and results from the presence of meningocytes outside the calvarium.
A cutaneous myxoma, or superficial angiomyxoma, consists of a multilobulated myxoid mass containing stellate or spindled fibroblasts with pools of mucin forming cleft-like spaces. There is often a proliferation of blood vessels and an inflammatory infiltrate. Staining is positive for vimentin, negative for cytokeratin and desmin, and variable for CD34, Factor VIIIa, SMA, MSA and S-100.
Trichoepithelioma is a neoplasm of the adnexa of the skin. Its appearance is similar to basal cell carcinoma.
Sebaceous carcinoma, also known as sebaceous gland carcinoma (SGc), sebaceous cell carcinoma, and meibomian gland carcinoma is an uncommon malignant cutaneous tumor. Most are typically about 1.4 cm at presentation. SGc originates from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. SGc can be divided into 2 types: periocular and extraocular. The periocular region is rich in sebaceous glands making it a common site of origin. The cause of these lesions in the vast majority of cases is unknown. Occasional cases may be associated with Muir-Torre syndrome. SGc accounts for approximately 0.7% of all skin cancers, and the incidence of SGc is highest in Caucasian, Asian, and Indian populations. Due to the rarity of this tumor and variability in clinical and histological presentation, SGc is often misdiagnosed as an inflammatory condition or a more common neoplasm. SGc is commonly treated with wide local excision or Mohs micrographic surgery, and the relative survival rates at 5 and 10 years are 92.72 and 86.98%, respectively.
Pigmented hairy epidermal nevus syndrome, also known as Becker's naevus syndrome, is a cutaneous condition characterized by a Becker nevus, ipsilateral hypoplasia of the breast, and skeletal defects such as scoliosis.
Koenen's tumor (KT), also commonly termed periungual angiofibroma, is a subtype of the angiofibromas. Angiofibromas are benign papule, nodule, and/or tumor lesions that are separated into various subtypes based primarily on the characteristic locations of their lesions. KTs are angiofibromas that develop in and under the toenails and/or fingernails. KTs were once considered as the same as another subtype of the angiofibromas viz., acral angiofibromas. While the literature may still sometimes regard KTs as acral angiofibromas, acral angiofibromas are characteristically located in areas close to but not in the toenails and fingernails as well as in the soles of the feet and palms of the hands. KTs are here regarded as distinct from acral angiofibromas.
Spiradenomas (SA) are rare, benign cutaneous adnexal tumors that may progress to become their malignant counterparts, i.e. spiradenocarcinomas (SAC). Cutaneous adnexal tumors are a group of skin tumors consisting of tissues that have differentiated towards one of the four primary adnexal structures found in normal skin: hair follicles, sebaceous sweat glands, apocrine sweat glands, and eccrine sweat glands. SA and SAC tumors were regarded as eccrine gland tumors and termed eccrine spiradenomas and eccrine spiradenocarcinomas, respectively. However, more recent studies have found them to be hair follicle tumors and commonly term them spiradenomas and spiradenocarcinomas, respectively. Further confusing the situation, SA-like and SAC-like tumors are also 1) manifestations of the inherited disorder, CYLD cutaneous syndrome (CCS), and 2) have repeatedly been confused with an entirely different tumor, adenoid cystic carcinomas of the salivary gland. Here, SA and SAC are strictly defined as sporadic hair follicle tumors that do not include the hereditary CCS spiradenomas and heridtary spiradenocarcinoms of CCS or the adenoid cystic carcinomas.
Malignant pilomatricoma is a cutaneous condition characterized by a locally aggressive tumor composed of hair-matrix cells.
A ghost cell is an enlarged eosinophilic epithelial cell with eosinophilic cytoplasm but without a nucleus. It has lost its nucleus and cytoplasmic contents, leaving behind only the cell membrane and sometimes remnants of the cell's structure. In pathology, ghost cells are often associated with certain types of tumors, such as pilomatricomas and calcifying odontogenic cysts, where they appear as pale, anucleate cells that have undergone degeneration or calcification.
CYLD cutaneous syndrome (CCS) encompasses three rare inherited cutaneous adnexal tumor syndromes: multiple familial trichoepithelioma (MFT1), Brooke–Spiegler syndrome (BSS), and familial cylindromatosis (FC). Cutaneous adnexal tumors are a large group of skin tumors that consist of tissues that have differentiated towards one of the four primary adnexal structures found in normal skin: hair follicles, sebaceous sweat glands, apocrine sweat glands, and eccrine sweat glands. CCS tumors are hair follicle tumors.
