Back Mass

It is not uncommon for a patient to complain of a lump on his or her back. Most of the time, the lesion is a sebaceous cyst or lipoma. However, there are other types of back masses, and a simple method of recall is needed. Anatomy is the key. If the mnemonic MINT is applied to most of these structures, all of the important lesions can be recalled.


  • M—Malformations include pilonidal cysts and sebaceous cysts.

  • I—Inflammation suggests carbuncles and furuncles.

  • N—Neoplasms include hemangiomas, neurofibromas, lipomas, and metastatic tumors.

  • T—Trauma, of course, suggests contusions.

Subcutaneous Tissue and Fascia

  • M—Malformations include hernias of Petit triangle.

  • I—Inflammation suggests lesions such as rheumatoid nodules and abscesses.

  • N—Neoplasms encompass those mentioned above.

  • T—Trauma includes contusions and lacerations. Anasarca may produce edema of the back.


Muscle is frequently nodular in fibromyositis, and a bursa may occasionally swell significantly. Rupture of a muscle or ligament and contusions are traumatic lesions that may present a mass. Muscle spasm from back injuries is often significant enough to cause a “mass.”


Lesions of the bone are usually responsible for the deeper masses in the back.

  • M—Malformations include spina bifida, which may be occult or manifest as a swelling such as meningocele or meningomyelocele.

  • I—Inflammation suggests the gibbus of Pott disease (tuberculosis of the spine).

  • N—Neoplasm suggests metastatic neoplasm and multiple myeloma of the spine which may protrude from beneath the skin.

  • T—Trauma suggests the obvious mass of a fracture dislocation or hematoma of the periosteum of the spine.

Retroperitoneal Structure

Wilms tumors of the kidney and perinephric abscesses may present as a mass in the back.

Approach to the Diagnosis

With skin lesions, excision or biopsy is frequently the best approach. Masses of the deeper structures cannot be approached as aggressively until certain conditions have been ruled out by computed tomography (CT) scans and bone scans. If a meningocele or similar congenital lesion is suspected, a neurosurgeon must be consulted.

Other Useful Tests

  • X-ray of the thoracic or lumbosacral spine (malformations, neoplasm)

  • Magnetic resonance imaging (MRI) of the thoracic or lumbar spine (malformation, neoplasm)

  • Intravenous pyelogram (IVP) (Wilms tumor, perinephric abscess)

  • Tuberculin test

  • Serum protein electrophoresis (multiple myeloma)

  • Myelogram

  • Exploratory surgery


A clever mnemonic to apply here is HAIR. The H stands for hereditary baldness and hormonal baldness, such as that caused by hypothyroidism and hyperthyroidism. The A stands for alopecia areata and autoimmune disease, such as lupus erythematosus. The I stands for inflammatory conditions, most notably tinea capitis, impetigo, or any condition associated with prolonged fever. The I also stands for intoxication, with arsenic and gold therapy most important here. Finally, the R stands for radiation. This is particularly significant today with so many victims of neoplasms being treated with this modality.

Approach to the Diagnosis

The Wood lamp and scrapings of any scaly material are useful in distinguishing tinea capitis from lupus and other disorders, but taking a skin biopsy of any unusual lesion is wise. Referral to a dermatologist is best if fungus or other infections are ruled out and the findings from thyroid function studies are normal. When there is diffuse hair loss, hypogonadism may be ruled out by ordering serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and estrogen.

Back mass.

Bleeding Under the Skin

Conditions of the skin, subcutaneous tissue, vascular wall, and blood may all be associated with bleeding under the skin or purpura; thus both anatomy and physiology must be used to develop this differential (Table 12). The skin may hemorrhage from infections such as smallpox, scabies, chickenpox, and measles, especially when the patient traumatizes the area to relieve the itching. A bug bite also may cause hemorrhage by this means. Focal and metastatic neoplasms may cause hemorrhage in the skin, whereas degeneration of the skin may lead to senile purpura. Trauma is by far the most common cause of hemorrhage of the skin.

The subcutaneous tissue is distinguished separately, so that one will recall the Ehlers–Danlos syndrome and pseudoxanthoma elasticum. The vascular wall may be damaged by numerous etiologies. The most important infectious etiologies are subacute bacterial endocarditis and meningococcemia, but typhoid fever, Weil disease, and Rocky Mountain spotted fever should not be forgotten. Systemic neoplasms that infiltrate the vascular wall (such as leukemia) are significant causes, but these usually cause purpura by inducing thrombocytopenia. Vascular degeneration and deficiency diseases (such as scurvy) are uncommon causes of purpura. Toxic conditions are more likely to be related to bone marrow suppression of platelets. Congenital lesions such as hereditary telangiectasias are important to remember.

Most important of all are the allergic and autoimmune disorders, because something can be done to alleviate the condition (e.g., steroids or immunosuppressants). Henoch–Schönlein purpura is a significant form

of allergic vasculitis, but periarteritis nodosa is important as well. Trauma is just as important here as in the skin. Thus, a ruptured varicose vein, crush injury, whooping cough, or contusions are important causes of purpura. Endocrine disorders also cause vascular purpura (as in Cushing syndrome).

Table 12 Bleeding Under the Skin (Purpura)

Allergic and Autoimmune
Skin   Smallpox
Focal and metastatic neoplasms Senile purpura       Bug bite
Scratching (most common cause)
Subcutaneous Tissue           Ehlers–Danlos syndrome
Pseudoxanthoma elasticum
Vascular Wall   Subacute bacterial endocarditis
Typhoid fever
Weil disease
Rocky Mountain spotted fever
Leukemia (systemic neoplasm) Scurvy Telangiectasis (hereditary)
Von Willebrand disease
Henoch–Schönlein purpura
Periarteritis nodosa
  Ruptured varicose vein
Crush injury
Whooping cough
Cushing syndrome
Waterhouse–Friderichsen syndrome
Blood     Leukemia
Myelophthisic anemia
Aplastic anemia Gold injection
Salicylate ingestion
Potassium iodide
Quinidine Ergot, heparin, and dicoumarol therapy
Salicylate toxicity
von Willebrand disease
Hereditary thrombasthenia
Idiopathic thrombocytopenia
Lupus erythematosus

Bleeding under the skin.

Disorders of the blood figure prominently in purpura. Significant among these are the numerous disorders that cause suppression or increased destruction of platelets. Toxic disorders such as gold injections, salicylate ingestion, potassium iodide, quinidine, ergot, and chloral hydrate are just a few of these. It is best to assume that any drug
may cause purpura until proven otherwise. Leukemic overgrowth of the bone marrow may cause purpura because of thrombocytopenia, but any neoplasm that infiltrates the marrow (myelophthisic anemia) must be considered. Autoimmune disease suggests the purpura of idiopathic thrombocytopenic purpura (ITP) and lupus erythematosus.

Sep 23, 2018 | Posted by in CRITICAL CARE | Comments Off on B

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