PSN are diagnosed by examining the tissue under a microscope, usually obtained with a dilation and curettage.

Typically, they consist of pink (hyaline) material using the standard stain and contain few cells. Bizarre multinucleated cells may be present; however, there is no mitotic activity. The differential diagnosis includes (cervical) squamous cell carcinoma and exaggerated placental site.

PSN are benign. Once removed, they do not require any treatment and do not recur.

Colloid nodules are usually small enough to be undetectable without an ultrasound or other imaging techniques. They usually produce no symptoms, so patients are unlikely to notice them until their size makes them easier to detect. Like other thyroid nodules, they are usually first noticed in a routine physical examination.

The clinical management of a cyst of Montgomery depends upon the symptoms of the patient.

If there are no signs of infection, a cyst of Montgomery can be observed, because more than 80% resolve spontaneously, over only a few months. However, in some cases, spontaneous resolution may take up two years. In such cases, a repeat ultrasonography may become necessary. If, however, the patient has signs of an infection, for example reddening (erythema), warmth, pain and tenderness, a treatment for mastitis can be initiated, which may include antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs). With treatment, inflammatory changes usually disappear quickly. In rare cases, drainage may become necessary. A surgical treatment of a cyst of Montgomery, i.e. a resection, may become necessary only if a cyst of Montgomery persists, or the diagnosis is questioned clinically.

The prognosis seems to be excellent. In one series, all adolescent patients with a cyst of Montgomery had a favourable outcome.

Fine Needle Aspiration Cytology (FNAC) is a cheap, simple, and safe method in obtaining cytological specimens for diagnosis by using a needle and a syringe. The "Bethesda System for Reporting Thyroid Cytopathology" is the system used to report whether the thyroid cytological specimen is benign or malignant. It can be divided into six categories:

Repeated FNAC is recommended for Category I, followed by clinical follow-up in Category II, repeat FNAC for Category III, and lobectomy for Category IV, near total-thyroidectomy/lobectomy for Category V, and near total thyroidectomy for Category VI. The risk of malignancy in a malignant FNAC report is 93.7% while for suspicious FNAC report, it is 18.9%.

Ultrasound imaging is useful as the first-line, non-invasive investigation in determining the size, texture, position, and vascularity of a nodule, accessing lymph nodes metastasis in the neck, and for guiding fine needle aspiration cytology (FNAC) or biopsy. High frequency transducer (7–12 MHz) is used to scan the thyroid nodule, while taking cross-sectional and longitudinal sections during scan. Suspicious findings in a nodule are hypoechoic, ill-defined margins, absence of peripheral halo or irregular margin, fine, punctate microcalcifications, presence of solid nodule, high levels of irregular blood flow within the nodule or "taller-than-wide sign" (anterior-posterior diameter is greater than transverse diameter of a nodule). Features of benign lesion are: hyperechoic, having coarse, dysmorphic or curvilinear calcifications, comet tail artifact (reflection of a highly calcified object), absence of blood flow in the nodule, and presence of cystic (fluid-filled) nodule. However, the presence of solitary or multiple nodules is not a good predictor of malignancy. Malignancy is only diagnosed when ultrasound findings and FNAC report are suggestive of malignancy. Another imaging modality, which is ultrasound elastography, is also useful in diagnosing thyroid malignancy especially for follicular thyroid cancer. However, it is limited by the presence of adequate amount of normal tissue around the lesion, calcified shell around a nodule, cystic nodules, coalescent nodules.

Colloid nodules may be initially identified as an unspecified kind of thyroid nodule. Follow-up examinations typically include an ultrasound if it's unclear whether or not there really is a nodule present. Once the presence of a nodule has been confirmed, the determination of the kind of thyroid nodule is done by fine needle aspiration biopsy.

Colloid nodules are distinguished by an apparently gelatinous mass of colloid both surrounding and contained within follicular cells. Colloid nodules are not surrounded by a fibrous capsule of compressed tissue. However, they are surrounded by flattened epithelial cells. Both the number of cells and the type of colloid may vary considerably.

A cyst of Montgomery may be asymptomatic. Yet, a cyst of Montgomery usually is diagnosed when a female patient, 10–20 years of age, complains to a healthcare professional of breast pain (mastalgia), inflammation or a palpable nodule in the breast. The diagnosis is made clinically, when a palpable nodule is felt in the retroareolar area.

The diagnosis can be confirmed with ultrasonography, frequently showing a simple cyst in the retroareolar area. In some patients, multiple cysts or bilateral cysts may exist. Cysts of Montgomery may have liquid content with an echogenic or calcific sediment.

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.

Thyroid oncocytomas can be benign (adenomas) or malignant (carcinomas). Grossly, oncocytic adenomas are encapsulated, solid nodules with a characteristic brown cut surface. The gross appearance of a minimally invasive oncocytic carcinoma is indistinguishable to that of an adenoma, while widely invasive oncocytic carcinomas are obviously invasive macroscopically and display pervasive vascular invasion with multifocal involvement of the thyroid gland. There are no reliable cytologic features which distinguish oncocytic adenomas from carcinomas and the only criterion for a diagnosis of malignancy is the identification of transcapsular or vascular invasion.

In gynecology, a Rokitansky nodule is a mass or lump in an ovarian teratomatous cyst.

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.

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.

Fibroma of tendon sheath is a benign tumor that presents as a small subcutaneous nodule that slowly increases in size. The tumors often have a multinodular growth pattern, with individual nodules being composed of bland, slender, spindle-shaped cells (myofibroblasts) in a dense, fibrous matrix.” A common microscopic finding is the presence of elongated, slit-like blood vessels. The lesions nearly always arise in the distal portions of the extremities. They often occur on the fingers, hands, toes, or feet. Although they are benign, they may recur in up to 40% of cases.

Although they may be regarded as a tumor of the skin, the lesions arise from tendons and aponeuroses in superficial sites, and are therefore properly classified as in the category "soft tissue tumor."

The biological nature of Fibroma of tendon sheath is not known, but the category appears to comprise a number of different pathologic processes. It is considered that about one-third of the lesions in this category may be acral variants of the entity, nodular fasciitis.

Microcystic adnexal carcinoma (also known as sclerosing sweat duct carcinoma) is a cutaneous condition characterized by a slow-growing plaque or nodule.

A sebaceous adenoma, a type of adenoma, a cutaneous condition characterized by a slow-growing tumor usually presenting as a pink, flesh-coloured, or yellow papule or nodule.

Solitary cutaneous leiomyoma typically presents as a deeply circumscribed, freely movable, rounded nodule ranging from 2 to 15mm in diameter, with overlying skin that may have a reddish or violaceous tint.

Fibrous hamartoma of infancy is a rapidly growing, painless, ill-defined subcutaneous or intradermal nodule that is generally solitary and less than 5 cm in size, though, rarely, multiple lesions occur synchronously.

By 1999, there were 12 reported cases.

The majority of patients are less than 2 years old, with 25% of cases being congenital. Possible locations include the trunk and limbs; usually the upper arm or shoulder. Local excision is the treatment of choice, but it may recur locally.

Polypoid lesions of the gallbladder affect approximately 5% of the adult population. The causes are uncertain, but there is a definite correlation with increasing age and the presence of gallstones (cholelithiasis). Most affected individuals do not have symptoms. The gallbladder polyps are detected during abdominal ultrasonography performed for other reasons.

The incidence of gallbladder polyps is higher among men than women. The overall prevalence among men of Chinese ancestry is 9.5%, higher than other ethnic types.

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.

Most polyps are benign and do not need to be removed. Polyps larger than 1 cm with co-occurring gallstones occurring in people over the age of 50 may have the gallbladder removed (cholecystectomy), especially if the polyps are several or appear malignant. Laparoscopic surgery is an option for small or solitary polyps.

A trumpeter's wart is a cutaneous condition characterized by a firm, fibrous, hyperkeratotic nodule on the upper lip of a trumpet player.

Since Rokitansky–Aschoff sinuses can be normally present in the gall badder without any pathology, the radiological detection of these is only of academic interest. Magnetic resonance imaging plays an important role in the diagnosis of Rokitansky–Aschoff sinuses.

Angiolipoma is a subcutaneous nodule with vascular structure, having all other features of a typical lipoma. They are commonly painful.

Syringofibroadenoma (also known as "acrosyringeal nevus of Weedon and Lewis") is a cutaneous condition characterized by a hyperkeratotic nodule or plaque involving the extremities.

It is considered of eccrine origin.