Lipomatosis is believed to be a hereditary condition in which multiple lipomas are present on the body.

Adiposis dolorosa (Dercum disease) is a rare condition involving multiple painful lipomas, swelling, and fatigue. Early studies mentioned prevalence in obese postmenopausal women. However, current literature demonstrates that Dercum disease is present in more women than men of all body types; the average age for diagnosis is 35 years.

Benign symmetric lipomatosis (Madelung disease) is another condition involving lipomatosis. It nearly always appears in middle-aged males after many years of alcoholism. But, non-alcoholics and females can also be affected.

An oncocytoma is a tumor made up of oncocytes, epithelial cells characterized by an excessive amount of mitochondria, resulting in an abundant acidophilic, granular cytoplasm. The cells and the tumor that they compose are often benign but sometimes may be premalignant or malignant.

The tendency to develop a lipoma is not necessarily hereditary, although hereditary conditions such as familial multiple lipomatosis might include lipoma development. Genetic studies in mice have shown a correlation between the "HMG I-C" gene (previously identified as a gene related to obesity) and lipoma development. These studies support prior epidemiologic data in humans showing a correlation between "HMG I-C" and mesenchymal tumors.

Cases have been reported where minor injuries are alleged to have triggered the growth of a lipoma, called "post-traumatic lipomas." However, the link between trauma and the development of lipomas is controversial.

Spiradenoma, also spiroma or eccrine spiradenoma, is a cutaneous condition that is typically characterized, clinically, as a solitary, deep-seated dermal nodule of approximately one centimeter, occurring on the ventral surface of the body. Spiradenoma lesions are benign sudoriferous tumors, and have also been described as cystic epitheliomas of the sweat glands.

The histological origin is controversial.

Patients with thyroid oncocytomas present with a thyroid nodule, usually with normal thyroid function. If the tumor is big or invasive, there may be other symptoms such as difficulty swallowing or talking.

A physician's response to detecting an adenoma in a patient will vary according to the type and location of the adenoma among other factors. Different adenomas will grow at different rates, but typically physicians can anticipate the rates of growth because some types of common adenomas progress similarly in most patients. Two common responses are removing the adenoma with surgery and then monitoring the patient according to established guidelines.

One common example of treatment is the response recommended by specialty professional organizations upon removing adenomatous polyps from a patient. In the common case of removing one or two of these polyps from the colon from a patient with no particular risk factors for cancer, thereafter the best practice is to resume surveillance colonoscopy after 5–10 years rather than repeating it more frequently than the standard recommendation.

Pituitary adenomas are seen in 10% of neurological patients. A lot of them remain undiagnosed. Treatment is usually surgical, to which patients generally respond well. The most common subtype, prolactinoma, is seen more often in women, and is frequently diagnosed during pregnancy as the hormone progesterone increases its growth. Medical therapy with cabergoline or bromocriptine generally suppresses prolactinomas; progesterone antagonist therapy has not proven to be successful.

Papillary eccrine adenoma (also known as "tubular apocrine adenoma") is a cutaneous condition characterized by an uncommon benign sweat gland neoplasm that presents as a dermal nodule located primarily on the extremities of black patients.

A poroma is a benign skin tumor derived from sweat glands. Although the original term "poroma "was initially used to describe a tumor derived from the ductal epithelium of eccrine sweat glands, the term is used in general reference to tumors derived from ductal portions of both eccrine and apocrine sweat glands. Specific sub-types are primarily defined by location of tumor, and include:

- eccrine poroma

- hidroacanthoma simplex (intraepithelial poroma)

- dermal duct tumor (intradermal poroma)

- syringoacanthoma

- syringofibroadenoma

- poroid hidradenoma ("disputed as different family")

Treatment may include the following:

- Surgery with or without radiation

- Radiotherapy

Fast neutron therapy has been used successfully to treat salivary gland tumors, and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.

- Chemotherapy

Pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components, having a malignant potentiality. It is the most common type of salivary gland tumor and the most common tumor of the parotid gland. It derives its name from the architectural Pleomorphism (variable appearance) seen by light microscopy. It is also known as "Mixed tumor, salivary gland type", which describes its pleomorphic appearance as opposed to its dual origin from epithelial and myoepithelial elements.

Little is known about the total incidence of salivary gland tumours as most benign tumours go unrecorded in national cancer registries. The majority of salivary tumours are benign (65-70%). Within the parotid gland 75 - 80% of tumours are benign. Around 50% of the tumours found in the submandibular glands are benign. Sublingual gland tumours are very rare but if present, they are most likely to be malignant.

In the United States, salivary gland cancers are uncommon with an incidence rate of 1.7 in 100000 between 2009 and 2013.

Hidradenoma (also known as acrospiroma, from "akral ""peripheral"" + spiroma ""epithelial tumor of sweat gland") refers to a benign adnexal tumor of the apical sweat gland. Another name for Hidradenoma is Cystadenoma and Hydrocystadenomas. These are 1–3 cm translucent blue cystic nodules.It usually presents as a single, small skin-colored lesion, and is considered distinct from the closely related poroma. Hidradenomas are often sub-classified based on subtle histologic differences, for example:

- clear-cell hidradenoma or acrospiroma

- nodular hidradenoma or acrospiroma

- solid-cystic hidradenoma

Discussion of sweat gland tumors can be difficult and confusing due to the complex classification and redundant terminology used to describe the same tumors. For example, acrospiroma and hidradenoma are synonymous, and sometimes the term "acrospiroma" is used to generally describe benign sweat gland tumors. In addition, a single lesion may contain a mixture of cell-types. There has also been a change in understanding about how tumors that were previously believed to strictly derive from specific sweat gland types may, in fact, derive from both eccrine "or" apocrine glands.

Hidradenomas are by definition benign, with malignant transformation very rare. When tumors show malignant characteristics, they are known as hidradenocarcinoma. Surgical excision is usually curative and local recurrences are rare, although malignant tumors may metastasize.

Benign lymphoepithelial lesion is a type of benign enlargement of the parotid and/or lacrimal glands. This pathologic state is sometimes, but not always, associated with Sjögren's syndrome.

Benign tumors are very diverse, and may be asymptomatic or may cause specific symptoms depending on their anatomic location and tissue type. They grow outwards, producing large rounded masses, which can cause what is known as a "mass effect". This growth can cause compression of local tissues or organs, which can cause many effects such as blockage of ducts, reduced blood flow (ischaemia), tissue death (necrosis) and nerve pain or damage. Some tumors also produce hormones that can lead to life-threatening situations. Insulinomas can produce large amounts of insulin leading to hypoglycemia. Pituitary adenomas can cause elevated levels of hormones such as growth hormone and insulin-like growth factor-1, which cause acromegaly; prolactin; ACTH and cortisol, which cause Cushings disease; TSH, which causes hyperthyroidism; and FSH and LH. Bowel intussusception can occur with various benign colonic tumors. Cosmetic effects can be caused by tumors, especially those of the skin, possibly causing psychological effects on the person with the tumor. Vascular tumors can bleed, which in some cases can be substantial, leading to anemia.

PTEN hamartoma syndrome comprises four distinct hamartomatous disorders characterised by genetic mutations in the PTEN gene; Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome and Proteus-like syndrome. Although they all have distinct clinical features, the formation of hamartomas is present in all four syndromes. PTEN is a tumor suppressor gene that is involved in cellular signalling. Absent or dysfunctional PTEN protein allows cells to over-proliferate, causing hamartomas.

Cowden syndrome is an autosomal dominant genetic disorder characterised by multiple benign hamartomas (trichilemmomas and mucocutaneous papillomatous papules) as well as a predisposition for cancers of multiple organs including the breast and thyroid. Bannayan-Riley-Ruvalcaba syndrome is a congenital disorder characterised by hamartomatous intestinal polyposis, macrocephaly, lipomatosis, hemangiomatosis and glans penis macules. Proteus syndrome is characterised by nevi, asymmetric overgrowth of various body parts, adipose tissue dysregulation, cystadenomas, adenomas, vascular malformation.

A 2006 review stated that RS often leads renal cancer between ages 30-50. Renal cancer kills about 1 in 3 people, but 5-year survival rates improved between 1974-1976 and 1995-2000, from 52% to 64%.

A variant of eccrine spiradenoma which can be multiple on the scalp and can coalesce to form a 'Turban' tumour. In pathology, a cylindroma is a tumour with nests of cells that resemble a cylinder in cross section.

Types include:

- Dermal eccrine cylindroma, a benign tumour of the skin

- Adenoid cystic carcinoma, a malignant tumour of the salivary gland

Hidradenocarcinoma (also known as malignant hidradenoma, malignant acrospiroma, clear cell eccrine carcinoma, or primary mucoepidermoid cutaneous carcinoma) is a malignant adnexal tumor of the sweat gland. It is the malignant variant of the benign hidradenoma. It may develop de novo or in association with an existent hidradenoma.

This type of tumor typically develops in older individuals (after age 40).

Overall, the mainstay of the treatment for salivary gland tumor is surgical resection. Needle biopsy is highly recommended prior to surgery to confirm the diagnosis. More detailed surgical technique and the support for additional adjuvant radiotherapy depends on whether the tumor is malignant or benign.

Surgical treatment of parotid gland tumors is sometimes difficult, partly because of the anatomical relationship of the facial nerve and the parotid lodge, but also through the increased potential for postoperative relapse. Thus, detection of early stages of a tumor of the parotid gland is extremely important in terms of prognosis after surgery.

Generally, benign tumors of the parotid gland are treated with superficial(Patey's operation) or total parotidectomy with the latter being the more commonly practiced due to high incidence of recurrence. The facial nerve should be preserved whenever possible. The benign tumors of the submandibular gland is treated by simple excision with preservation of mandibular branch of the trigeminal nerve, the hypoglossal nerve, and the lingual nerve. Other benign tumors of minor salivary glands are treated similarly.

Malignant salivary tumors usually require wide local resection of the primary tumor. However, if complete resection cannot be achieved, adjuvant radiotherapy should be added to improve local control. This surgical treatment has many sequellae such as cranial nerve damage, Frey's syndrome, cosmetic problems, etc.

Usually about 44% of the patients have a complete histologic removal of the tumor and this refers to the most significant survival rate.

A papillary hidradenoma, also hidradenoma papilliferum, is a sharply circumscribed nodule or benign tumor of the apocrine gland usually found on the labia majora or the interlabial folds. It is benign tissue (not cancerous) but is often confused clinically with carcinoma of the vulva because of its tendency to ulcerate.

Lipoblastoma is a type of subcutaneous benign fatty tumor.

Types include:

- Benign lipoblastomatosis, a tumor, also known as an embryonic lipoma, which usually occurs in children under three years old. This is the tumor of brown fat cells.

- Myxoid lipoblastoma, a cutaneous condition characterized by excess mucin

In 80% of cases, the parotid gland is affected. Lacrimal glands are also affected.

Mucinous cystadenoma is a benign cystic tumor lined by a mucinous epithelium. It is a type of cystic adenoma (cystadenoma).

Mucinous cystadenoma may arise in a number of locations; however, mucinous cystadenoma at different locations are not generally considered to be related to one another.

Mesenchymal neoplasms of the gallbladder are rare and in particular leiomyomas of the gallbladder have been rarely reported, all of them in patients with immune system disorders. Although, recently, a case was reported in absence of associated immunodeficiency at Monash Hospital in Melbourne Australia in a healthy 39-year-old woman with no symptoms.